What American President did not marry?

The defining moment in Giuliani's career was his management of the September 11, 2001 attacks on the World Trade Center. His public visibility in the days following the attacks earned him the nickname "America's Mayor." Since leaving office as Mayor of New York, Giuliani has pursued business and legal interests, and has remained politically active by campaigning for Republican candidates for political offices at all levels. On November 13, 2006, he formed an exploratory committee to consider entering the 2008 Presidential Campaign. and is expected to declare his candidacy.