Today is Wednesday, April 20, the 111th day of 2016. There are 255 days left in the year.

On this date:

In 1861, Col. Robert E. Lee resigned his commission in the United States Army. (Lee went on to command the Army of Northern Virginia, and eventually became general in-chief of the Confederate forces.)

In 1863, President Abraham Lincoln signed a proclamation admitting West Virginia to the Union, effective in 60 days. (on June 20, 1863.)

In 1912, Boston’s Fenway Park hosted its first professional baseball game while Navin Field (Tiger Stadium) opened in Detroit. (The Red Sox defeated the New York Highlanders 7-6 in 11 innings; the Tigers beat the Cleveland Naps 6-5 in 11 innings.)

In 1914, the Ludlow Massacre took place when the Colorado National Guard opened fire on a tent colony of striking miners; about 20 (accounts vary) strikers, women and children died.

In 1986, following an absence of six decades, Russianborn pianist Vladimir Horowitz performed in the Soviet Union to a packed audience at the Grand Hall of the Tchaikovsky Conservatory in Moscow.

In 1999, the Columbine High School massacre took place in Colorado as two students, Eric Harris and Dylan Klebold, shot and killed 12 classmates and one teacher before taking their own lives.