Why is the election on Tuesday November 8?
The election is in November because America was predominently an ag grarian society and November was the quietest for rural workers. It is always traditionally on a Tuesday to allow people living in rural areas time to travel to towns and cities to vote, removing the need to travel on a Sunday.
It is always the first Tuesday after the first Monday to avoid the election falling on November 1st. This was to avoid clashing with All Saints Day and the day when businessmen traditionally did their accounting from the previous month.