June 19 each year is known as Juneteenth, a combination of the words June and nineteenth. It is a day of celebration, but one that has not been widely understood or known outside African-American communities.This column addresses the date and its history.The Emancipation ProclamationPresident Abraham Lincoln issued his Emancipation Proclamation on Sept. 22, 1862, which took effect on Jan. 1, 1863. The executive order began:“That on the first day of January, in the year of our Lord one thousand eight hundred and sixty …