(CNN) Juneteenth is the oldest known US celebration of the end of slavery. African-Americans and others mark the anniversary much like the Fourth of July, with parties, picnics and gatherings with family and friends. Here's a look at Juneteenth, also called Emancipation Day, by the numbers:

154 - Years since Maj. Gen. Gordon Granger (Union Army) first read the proclamation, General Orders, No. 3, in Years since Maj. Gen. Gordon Granger (Union Army) first read the proclamation, General Orders, No. 3, in Galveston, Texas, notifying slaves of their emancipation, on June 19, 1865.

January 1, 1863 - Date President Abraham Lincoln issued the final Date President Abraham Lincoln issued the final Emancipation Proclamation, freeing those enslaved.

901 - Days in between the issuance of the Emancipation Proclamation and General Orders, No. 3.

13th - Amendment to the US Constitution that abolished slavery.