As mayor he took an active part in overseeing the construction of the present City Hall. Some offices of the new building were occupied in 1898, though the building was not finally completed until 1904. An Ordinance of 1900 authorized the mayor to appoint a factory inspector to look for violations of state laws regulating hours of work, sanitary conditions and restrictions on the employment of children. In 1900 he approved an ordinance authorizing the start of construction on the City Hospital, which had been damaged extensively in the Tornado of 1896.

Laws passed by the Missouri Legislature have always affected the mayor´s administration of the City´s government. An 1899 law required the City to appropriate the sum certified by the board of police commissioners as necessary to run the Police Department each year. Any City official violating the act was subject to a fine of $1,000. In the election of 1900, the people of Missouri approved a $5,000,000 bond issue to finance the St. Louis World´s Fair of 1904.

Mayor Ziegenhein was born on a farm in St. Louis County in 1845 and came to the City to start his apprenticeship at the carpenter´s trade. At the start of the Civil War he was 17 years old. After serving in the Union Army, he returned to St. Louis and started a contracting and building business. In 1869 he married Miss Catherine Henkle. They had nine children.

In later years Mayor Ziegenhein took an active part in directing the financial affairs of the Lafayette Bank, an institution in which he was one of the largest stockholders. He died in 1910. Interment was at New St. Marcus Cemetery in St. Louis.