Between 1788 and 1845, states decided their own voting dates. In 1792, a law was passed mandating that state elections be held within a 34-day period before December, so most elections took place in November. By November the harvest was finished but winter had not begun, so it made for a good time to vote.
During the late 18th and early 19th centuries, communication was
slow, so results took weeks to announce, but with the advent of the
railroad and telegraph, Congress decided it was time to standardize
Monday was out, because it would require people to travel to the
polls by buggy on the Sunday Sabbath. Wednesday was not an option,
because it was market day, and farmers would not be able to make it
to the polls. So it was decided that Tuesday would be the day that
Americans would vote in elections.
In 1845, Congress passed a law that presidential elections would be
held on the first Tuesday after the first Monday in November.