The U.S. Navy commissions its first class of diesel-powered submarines. Date: February 14, 1912 Read more on Wikipedia → 📅 Other events on February 14 📅 Events on this day in 1912 📅 On This Day (Today)

Arizona is admitted as the 48th and the last contiguous U.S. state. Date: February 14, 1912 Read more on Wikipedia → 📅 Other events on February 14 📅 Events on this day in 1912 📅 On This Day (Today)

Soviet Russia adopts the Gregorian calendar. Date: February 14, 1918 Read more on Wikipedia → 📅 Other events on February 14 📅 Events on this day in 1918 📅 On This Day (Today)

The Polish–Soviet War begins. Date: February 14, 1919 Read more on Wikipedia → 📅 Other events on February 14 📅 Events on this day in 1919 📅 On This Day (Today)

The League of Women Voters is founded in Chicago. Date: February 14, 1920 Read more on Wikipedia → 📅 Other events on February 14 📅 Events on this day in 1920 📅 On This Day (Today)

The Computing-Tabulating-Recording Company changes its name to International Business Machines Corporation (IBM). Date: February 14, 1924 Read more on Wikipedia → 📅 Other events on February 14 📅 Events on this day in 1924 📅 On This Day (Today)

Saint Valentine's Day Massacre: Seven people, six of them gangster rivals of Al Capone's gang, are murdered in Chicago. Date: February 14, 1929 Read more on Wikipedia → 📅 Other events on February 14 📅 Events on this day in 1929 📅 On This Day (Today)

World War II: German battleship Bismarck is launched. Date: February 14, 1939 Read more on Wikipedia → 📅 Other events on February 14 📅 Events on this day in 1939 📅 On This Day (Today)

World War II: Battle of Pasir Panjang contributes to the fall of Singapore. Date: February 14, 1942 Read more on Wikipedia → 📅 Other events on February 14 📅 Events on this day in 1942 📅 On This Day (Today)

World War II: Tunisia Campaign: General Hans-Jürgen von Arnim's Fifth Panzer Army launches a counter-attack against Allied positions in Tunisia. Date: February 14, 1943 Read more on Wikipedia → 📅 Other events on February 14 📅 Events on this day in 1943 📅 On This Day (Today)