American Revolutionary War: Ships of the Continental Navy fail in their attempt to capture a Royal Navy dispatch boat.
American Civil War: The Battle of Shiloh begins: In Tennessee, forces under Union General Ulysses S. Grant meet Confederate troops led by General Albert Sidney Johnston.
In Athens, the opening of the first modern Olympic Games is celebrated, 1,500 years after the original games are banned by Roman emperor Theodosius I.
World War I: The United States declares war on Germany (see President Woodrow Wilson's address to Congress).
Mohandas Karamchand Gandhi orders a general strike.
World War II: Nazi Germany launches Operation 25 (the invasion of Kingdom of Yugoslavia) and Operation Marita (the invasion of Greece).
Vietnam War: Easter Offensive: American forces begin sustained air strikes and naval bombardments.
The Bosnian War begins.
Pakistan tests medium-range missiles capable of reaching India.