Other presidents elected on November 6 include Lincoln, Cleveland (first term), McKinley, Hoover, and Eisenhower. The election of 1900, which saw McKinley-Roosevelt win handily over Bryan-Stevenson, would have been a November 5 election, except for the fact that 1900 was not a leap year. In the Gregorian calendar, all years divisible by four are leap years except for years divisible by 100 -- such as 1800, 1900 -- that aren't themselves divisible by 400 -- such as 1600, 2000.
The election of 1860 was clearly the most momentous of the November 6 elections -- of any U.S. presidential election, it is easy to argue.
As Susan Schulten wrote in the New York Times, "Abraham Lincoln won a decisive victory on Nov. 6, 1860, with more than double the Electoral College votes of John C. Breckinridge, the runner-up. The election also sparked a crisis where 11 Southern states left the union, formed a new country and fell into a disastrous war with the North, all within six months of Lincoln’s win."