Today, Inauguration Day, countless references will have been made to Donald J. Trump as the 45th President of the United States.
To understand why President Trump is number 45, it is necessary to go back to the two terms of Grover Cleveland. Cleveland was the only president who had non-consecutive terms of office.
Cleveland was first elected as the 22nd president, for a term from 1885 to 1889. In the next election, where he again won the popular vote, he lost in the Electoral College to Benjamin Harrison, who became the 23rd president, from 1889 to 1893. In the following election, Grover Cleveland won both the popular vote and the Electoral College and became the 24th president. The second term ran from 1893 to 1897.
So, in fact, the United States has, including Donald J. Trump, only had 44 men who have been president.