How was the election of 1840 different from other elections?

The 1840 presidential election was the only U.S. Presidential election in which four people who either had been or would become a U.S. President (Van Buren, Harrison, Tyler, and Polk) received at least one vote in the Electoral College.

Explanation:

in 1897, pershing became a tactical officer at west point, and that's where he was given the nickname "black jack." pershing's first name is "john," for which "jack" is a nickname, and he was a white man who commanded black troops. hence "black jack".

uncle sam would be tossing and turning in his grave : *)