The baroque building which gave the square its name was built in 1730. It was the headquarters of the city’s Stadtwehr militia when Frankfurt was an independent city state and also contained a prison. In the 18th century Frankfurt still had city walls and its own army. In 1833 during the Frankfurter Wachensturm, the Hauptwache was stormed in failed effort by a small revolutionary force. When Prussia annexed the city in 1866 and took over military activities, the Hauptwache lost this role.
The prison remained and the Hauptwache also became a police station. In 1904, the building was used as a café and remains one to this day. Heavily burned in World War II bombing, it was reopened in a provisional form with an altered roof in 1954. In 1967, with the building of the U-Bahn tunnel through the city, it was dismantled so it could be moved and rebuilt over the new underground U-Bahn station. The plaza has undergone another major renovation when the S-Bahn station for suburban trains was opened in 1978. [Wikipedia]
