May 15

Saturday 15, 2004:

The largest prime number to be discovered, 2^24036583 − 1, is found by Josh Findley and the GIMPS collaborative effort.

Wednesday 15, 1957:

Britain tests its first hydrogen bomb in Operation Grapple.

Thursday 15, 1941:

Baseball player Joe DiMaggio starts his record-breaking 56-game hitting streak.

Wednesday 15, 1918:

The US Post Office Department (later renamed the USPS) begins the first regular airmail service in the world (between New York City, Philadelphia and Washington, DC).

Sunday 15, 1864:

American Civil War: Battle of New Market, Virginia – Students from the Virginia Military Institute fight alongside the Confederate Army to force Union General Franz Sigel out of the Shenandoah Valley.

More on May, 15

• May, 15 in History
• People Born on May, 15
• They left us on May, 15