Complex sentence: The Amalgamated Center otherwise known as the Amalgamated Clothing Workers of America Office Building was built by the Bethany Brotherhood, which was funded by John Wanamaker, in 1900 and added to in 1912, and served as a working class social club and community center.
Split into simpler sentences: The Amalgamated Center otherwise known as the Amalgamated Clothing Workers of America Office Building was built by the Bethany Brotherhood, which was funded by John Wanamaker, in 1900. The building was added to in 1912, and served as a working class social club and community center.