Workers are shown repaving the road in front of the Philadelphia Zoo's Administration Building in the above June, 1934 picture. The Philadelphia Zoo is the first zoo in the United States, and was chartered on March 21, 1858, but its' opening was delayed until July 1, 1874 by the American Civil War. The zoo is located at the corner of 34th St. and Girard Ave. in Philadelphia's historic Fairmount Park.