1819 – Under terms of the Adams–Onís Treaty, Spain sells Florida to the United States for 5 million U.S. dollars.
1847 – In the Mexican–American War’s Battle of Buena Vista, 5000 American troops under the command of General Zachary Taylor, defeat 15,000 Mexican troops under the command of General Antonio López de Santa Anna (yes of Alamo and San Jacinto notoriety)
1856 – The United States Republican Party opens its first national convention in Pittsburgh.
1862 – Jefferson Davis is officially inaugurated for a 6 year term as the President of the Confederate States of America in Richmond, Virginia. He was previously inaugurated as a provisional president on February 18, 1861.
1872 – The Prohibition Party holds its first national convention in Columbus, Ohio, nominating James Black as its presidential nominee.
1878 – In Utica, New York, Frank Woolworth opens the first of many of five-and-dime Woolworth stores.
1889 – President Grover Cleveland signs into law a bill admitting North Dakota, South Dakota, Montana and Washington as U.S. states.
1909 – The 16 battleships of the Great White Fleet, led by USS Connecticut, return to the United States after a voyage around the world.
1942 – As Japanese victory becomes inevitable in the Philippines, President Roosevelt orders General Douglas MacArthur to evacuate to Australia.
1959 – Lee Petty wins the first Daytona 500 stock car race.
1974 –Reportedly inspired by the news reports of the buzzing of the White House by U.S. Army soldier Robert K. Preston in a stolen helicopter on February 17; Samuel Byck attempts to hijack a Delta Air Lines DC-9 jet at Baltimore/Washington International Airport with the intention of crashing it into the White House to assassinate President Nixon, but commits suicide aboard the aircraft after being shot and wounded by police.
1980 – In Lake Placid, New York, the United States Olympic hockey team defeats the Soviet Union hockey team 4–3.
1994 – CIA officer Aldrich Ames and his wife are charged with spying for the Soviet Union.
1997 – In Roslin, Midlothian, British scientists announce that an adult sheep named Dolly has been successfully cloned.
2018 – A Serbian man throws a grenade at the U.S embassy in Podgorica, Montenegro then detonates a suicide vest, managing to kill only himself and not even wound anyone else.