Government timeline By jpurd1 Jan 1, 1862 French Invasion of Mexico. Isolationism, Monroe Doctrine. Jan 1, 1898 Spanish-American War begins. Jan 1, 1899 Trade Wars in China. Jan 1, 1902 Panama Canal authorized. Jan 1, 1917 U.S. enters World War I. Jan 1, 1942 U.S. enters World War II. Jan 1, 1945 United Nations established. Jan 1, 1948 Berlin Blockade. Jan 1, 1950 Korean War begins. Jan 1, 1962 Cuban Missile Crisis. Jan 1, 1965 U.S. commits to Vietnam War. Jan 1, 1972 SALT I treaty. Jan 1, 1979 Soviet invasion of Afghanistan Jan 1, 1990 Operation Iraqi Freedom