What building was built earlier,  Manhattan Life Insurance Building or 15 Penn Plaza?
Manhattan Life Insurance Building The Manhattan Life Insurance Building was a 348 ft tower at 64-66 Broadway in New York City completed in 1894 to the designs of the architects of Kimball & Thompson and slightly extended north in 1904 making its new address 64-70 Broadway. It was the first skyscraper to pass 100 m in Manhattan.
Woolworth Building The Woolworth Building, at 233 Broadway, Manhattan, New York City, designed by architect Cass Gilbert and constructed between 1910 and 1912, is an early US skyscraper. The original site for the building was purchased by F. W. Woolworth and his real estate agent Edward J. Hogan by April 15, 1910, from the Trenor Luther Park Estate and other owners for $1.65 million. By January 18, 1911, Woolworth and Hogan had acquired the final site for the project, totaling $4.5 million. More than a century after its construction, it remains, at 241.4 m , one of the 100 tallest buildings in the United States as well as one of the 30 tallest buildings in New York City. It has been a National Historic Landmark since 1966, and a New York City landmark since 1983.