Twentieth Amendment to the United States Constitution
In the later part of the eighteenth century, when the Constitution was written, travel and communications were both very slow by modern standards. To cross the Atlantic Ocean could take several weeks. Traveling by horseback or by carriage on crude roads in the US could take even longer. Communications were mainly by letter or messenger. For these reasons the framers of the Constitution allowed for the longer periods of time it took to send and receive messages. Four months, the time from the election in November to the swearing-in in March, was necessary at the time.