Numerous steel and concrete skyscrapers were constructed in the first two decades of the 20th century. In the 1920s construction continued with skyscrapers such as the Aldine Trust Building, the Lewis Tower, the Drake Hotel, the Ben Franklin House and the Rittenhouse Plaza. In the early 1930s 30th Street Station, Convention Hall, and the Franklin Institute were constructed. In 1932 the United States' first International style skyscraper was built. The 631,006 sq.ft. PSFS Building, which was designed by George Howe and William Lescaze, was topped with the Philadelphia Savings Fund Society's initials in 27 ft red neon letters and is decorated with custom made interior detailing.