So the Civil War ended on April 9th 1865, Lincoln is assassinated on April 14th 1865 and the Titanic sank on April 15th 1912. Coincidence - I think not.
Also, the US entered WW1 on April 6th 1917 after the Lusitainia was sunk, on April 10th, 1945 Buchenwald was liberated, on April 12th 1861 The Civil War started at Fort Sumter SC, April 17th 1961 was the Bay of Pigs, April 18th 1775 was the Midnight Ride of Paul Revere (and several others), April 19th 1775 was "The Shot Heard Round the World", April 19th 1995 was the Oklahoma City bombing, April 26th 1986 - Chernobyl, April 27 1865 a steamship on the Mississippi River exploded killing 2000 Northern POW's returning home, April 28 1789 The Mutiny on the Bounty occurred in the Pitcairn Islands, also on April 28 1931 my mother was born, and on April 30th 1948 Israel became a recognized state.
Just thought I'd make it a bit more interesting.