From February 17th, 2026 through February 23rd, 2026, the military calendar brings together a striking mix of frontier skirmishes, civil war cities in flames, Pacific islands under bombardment, and armored columns racing across desert sands. This edition of “This Week in U.S. Military History” follows those threads across centuries, from early diplomacy on the Gulf Coast to modern combined-arms operations and the leap into space. Along the way we see how the United States expanded its strategic footprint, struggled over questions of loyalty and civil rights, and adapted to new technologies from submarines to strategic bombers and spacecraft. Some of these moments unfolded on distant battlefields, others inside presidential offices or remote atolls ringed by coral. All of them left marks on the way American forces fight, organize, and remember their own story. Together, they remind us that the same seven days can hold both battlefield heroism and difficult decisions far behind the lines.
Adams–Onís Treaty cedes Florida
On February 22nd, 1819, American and Spanish negotiators signed the Adams–Onís Treaty, transferring Spanish Florida to the United States and settling a long-troublesome frontier. For years, the border had been a patchwork where runaway enslaved people, Native communities, smugglers, and raiding parties moved in and out of reach of American authorities. Army expeditions under leaders like Andrew Jackson had already pushed deep into Spanish territory, showing how unstable the situation had become. By formally acquiring Florida, the United States gained control over key ports and coastal approaches to the Gulf of Mexico, which allowed planners to think more clearly about fortifications, naval stations, and defense in depth. The treaty also clarified boundaries farther west, shaping the map on which later campaigns in Texas and the Southwest would unfold. It was a diplomatic act, but it changed the strategic geometry of the southern United States for generations.
Open the Wiki entrySiege of the Alamo begins
On February 23rd, 1836, Mexican forces under Antonio López de Santa Anna arrived at San Antonio de Béxar and invested the small garrison holding the Alamo mission. The defenders were a mix of local Tejanos and volunteers from the United States who had joined the Texan cause, commanded by figures like William Barret Travis and James Bowie. Their position was poor in purely military terms: a converted mission with incomplete walls, limited artillery, and too few men to cover every approach. Yet when Santa Anna demanded surrender, the garrison chose to hold, setting the stage for a siege that would last nearly two weeks and end in their deaths. At the time, the fight was part of a regional rebellion, not U.S. national policy, but its memory quickly flowed into the broader American military tradition. The Alamo became a symbol of last-ditch resistance and sacrifice that later generations of American soldiers, especially in the Southwest, would recognize and invoke.
Open the Wiki entryClimax of the Battle of Buena Vista
By February 23rd, 1847, the Battle of Buena Vista in northern Mexico had reached its decisive phase. General Zachary Taylor’s outnumbered American force, including U.S. regulars and state volunteer regiments, faced a much larger army led by Santa Anna along a series of ridges and arroyos near Saltillo. The terrain allowed the Americans to anchor their line, but Santa Anna probed for weak points all day, at times driving back portions of the U.S. front. Volunteer formations, like the Mississippi Rifles, made hard-fighting counterattacks that helped stabilize the situation. As darkness fell, the American line still held, and Santa Anna chose to withdraw, claiming victory but abandoning the field. The outcome secured the U.S. position in northern Mexico and boosted Taylor’s reputation back home, helping propel him toward the presidency. Militarily, Buena Vista showed the importance of terrain, disciplined fire, and the ability of hastily raised volunteer units to endure heavy combat when well handled.
Open the Wiki entryHunley sinks USS Housatonic
On the night of February 17th, 1864, off Charleston, South Carolina, the Confederate submarine H. L. Hunley moved slowly toward the Union sloop of war USS Housatonic. The Hunley was a dangerous experiment: a hand-cranked, cigar-shaped boat with a spar torpedo mounted on its bow. Its crew had already died in earlier test accidents, but on this sortie the submarine reached its target, detonated its explosive charge, and sent Housatonic to the bottom in minutes. It was the first time in history that a submarine had successfully sunk an enemy warship in combat, and Union sailors suddenly had to contend with a new, unseen threat beneath the waves. The Hunley never returned from the mission, a reminder of how fragile early undersea technology could be. Even so, the attack foreshadowed the rise of submarine warfare in the twentieth century, when undersea fleets would reshape naval strategy on a global scale.
Open the Wiki entrySherman’s army captures Columbia, South Carolina
On February 17th, 1865, Union forces under Major General William Tecumseh Sherman entered Columbia, the capital of South Carolina, as part of the Carolinas campaign that followed the March to the Sea. Confederate defenses had crumbled, and the city’s fall carried heavy symbolic weight because South Carolina had led secession. That night, fires swept across large sections of Columbia. Accounts from the time conflict about how the fires started and who bore responsibility, but the result was the devastation of a major Southern city. For Union soldiers, the capture of Columbia helped disrupt Confederate rail lines, workshops, and supply depots that supported armies farther north in Virginia. For many Southerners, its destruction became a lasting image of the war’s harshest realities. Strategically, the city’s fall showed that Union armies could move deep through the interior of the Confederacy, unhinging its defenses and undermining morale in the war’s final months.
Open the Wiki entryUnion troops seize Wilmington, North Carolina
On February 22nd, 1865, Union forces completed the capture of Wilmington, North Carolina, after earlier seizing nearby Fort Fisher and fighting their way up the Cape Fear River. Wilmington had been the Confederacy’s last major Atlantic port, a vital outlet for blockade runners bringing in weapons, cloth, and other supplies from overseas. Once the harbor’s ring of forts fell and Union gunboats controlled the approaches, Confederate logistics took a severe blow. The loss of Wilmington meant that General Robert E. Lee’s army in Virginia could no longer count on seaborne imports slipping through the blockade to sustain it. Instead, Confederate armies had to rely on shrinking internal resources and increasingly fragile rail networks. The capture of the port also allowed Union planners to consider new avenues for moving troops and supplies along the coast. In the wider picture, Wilmington’s fall marked another tightening of the vise that would close on Richmond and Petersburg just weeks later.
Open the Wiki entryExecutive Order 9066 signed
On February 19th, 1942, a little more than two months after the attack on Pearl Harbor, President Franklin Roosevelt signed Executive Order 9066. The order authorized military commanders to establish exclusion zones and remove people from them, a power soon applied mainly along the West Coast. In practice, this meant that more than one hundred thousand people of Japanese ancestry, the majority of them American citizens, were forced from their homes and sent to inland camps under guard. Smaller numbers of German and Italian nationals were also affected, but the broadest impact fell on Japanese American communities. For the armed forces, the order created new responsibilities: guarding facilities, processing families, and managing vast restricted zones supposedly in the name of wartime security. Decades later, official reviews would conclude that fear, racism, and political pressure had outweighed sound military judgment. The episode remains a reminder that wartime decisions about security and loyalty can leave long shadows over both civil liberties and military institutions.
Open the Wiki entryOperation Hailstone and the opening of “Big Week”
In mid-February 1944, two linked air operations signaled how the United States was using airpower to reshape two different theaters of war. On February 17th, fast carriers of the U.S. Pacific fleet launched Operation Hailstone against Truk Lagoon, a major Japanese base in the Central Pacific. Waves of aircraft struck ships at anchor, airfields, and support installations, sinking and damaging a large portion of the enemy fleet’s local strength and reducing Truk’s value as a forward bastion. Just days later, beginning on February 20th, American heavy bombers in Europe opened the campaign popularly known as “Big Week,” a concentrated series of raids on German aircraft factories and related targets. Although losses were heavy, long-range escort fighters increasingly turned the air battle in favor of the Allies. Together, these operations showed how the United States was using sea-based and land-based airpower to hollow out enemy fleets and air forces before major ground offensives like the invasion of Normandy and the advance across the Central Pacific.
Open the Wiki entryMarines land on Iwo Jima
On February 19th, 1945, the beaches of Iwo Jima filled with landing craft as Marines of the 4th and 5th Marine Divisions came ashore under fire. The island was small but strategically important, lying between the Marianas and the Japanese home islands and hosting airfields that could threaten American bombers. Japanese defenders under General Tadamichi Kuribayashi had prepared a deeply dug-in defense, with tunnels, bunkers, and hidden artillery instead of the more exposed positions seen in earlier island battles. As Marines tried to climb the black volcanic sand, machine-gun and mortar fire cut into the waves of assault troops. Casualties were severe in the first hours, and it quickly became clear that the fight would be a prolonged struggle of attrition. For the U.S. Navy and Army Air Forces, seizing Iwo Jima promised emergency landing fields and fighter bases closer to Japan. For the Marines, the island became a test of endurance and small-unit leadership under conditions among the harshest of the Pacific war.
Open the Wiki entryFlag raised on Mount Suribachi
On February 23rd, 1945, a patrol from the 28th Marine Regiment climbed Mount Suribachi, the volcanic peak dominating the southern end of Iwo Jima, and raised an American flag. A larger flag soon replaced the first, and an Associated Press photographer captured the moment that would become one of the most reproduced images in military history. The photograph shows six Marines straining together to plant the flag, and for many Americans it came to symbolize the combined effort and sacrifice of the entire war in the Pacific. On the island itself, the moment boosted morale for troops still fighting among the island’s ridges and ravines. It did not, however, mark the end of the battle. Most of the casualties on Iwo Jima occurred after the flag raising, as Marines and supporting units pushed north against stubborn resistance. The image would later be used for war-bond drives and inspire the Marine Corps War Memorial near Washington, D.C., tying a specific day’s effort to a long legacy of remembrance.
Open the Wiki entryJohn Glenn orbits Earth in Friendship 7
On February 20th, 1962, Marine Corps officer John Glenn rode the spacecraft Friendship 7 into orbit atop an Atlas rocket, becoming the first American to orbit the Earth. The mission lasted only a few hours and three circuits of the planet, but it carried enormous importance in the Cold War competition for space. Glenn’s background as a fighter and test pilot linked early spaceflight directly to the skills and cultures of military aviation. Engineers and controllers watched anxiously as minor problems, including worries about a loose heat-shield indicator, forced adjustments to the flight plan and reentry. When the capsule splashed down safely and Glenn was recovered by Navy ships, it gave the United States a badly needed public success after earlier setbacks in the space race. For the armed forces, the mission highlighted how military aviators, tracking networks, and recovery forces would be central in the first generation of human spaceflight, foreshadowing later debates about space as a military domain.
Open the Wiki entryDesert Storm ground offensive opens overnight
On the night of February 23rd into February 24th, 1991, after weeks of intensive air strikes, coalition ground forces launched the main land offensive of Operation Desert Storm. U.S. Marine divisions attacked into Kuwait from the south, while U.S. Army armored corps and allied units executed a broad “left hook” across the desert into western Iraq to outflank Iraqi forces. Months of planning and rehearsal meant that units moved with speed and coordination, backed by artillery, attack helicopters, and close air support. Iraqi front-line positions, already battered from the air, often crumbled quickly, though pockets of resistance and difficult fighting certainly remained. The campaign liberated Kuwait in a matter of days and demonstrated the effectiveness of modern combined-arms maneuver supported by precision-guided munitions and real-time intelligence. For the U.S. military, Desert Storm became a showcase of the post-Vietnam, all-volunteer force and a reference point for doctrine, training, and public expectations in the decades that followed.
Open the Wiki entryAcross the Week
The events gathered in this week’s calendar show how American military power has always been about more than armies simply meeting in open battle. Diplomatic signatures in far-off capitals, desperate holds at missions on the frontier, and decisions made in Washington boardrooms can shape campaigns as surely as charges across ridgelines or landings on hostile beaches. From the seizure of Florida and the fall of Confederate ports to the air raids over Truk and the armored thrusts into Kuwait, geography and technology constantly reshaped what “defense” meant for the United States. At the same time, moments like the signing of Executive Order 9066 remind us that wartime choices carry human costs far from the front. Looking across these seven days, we see courage and innovation, but also the need for judgment and restraint. Remembering them together helps connect today’s service members and citizens to a long, complicated story of how the nation has used armed force.