English: Looking northwest at the construction site for the Washington Marriott Marquis hotel in Washington, D.C., in the United States in August 2011. Construction on the hotel had been in progress for about a year, with excavation having reached about 50 feet (15 m) below ground. Completion of the project was scheduled for May 2014. The building still standing is the headquarters of the United Association of Journeymen and Apprentices of the Plumbing and Pipe Fitting Industry (the Pipefitters union), a national trade union in the U.S. It was constructed in 1916 and designed in a Modernist-modified Chicago School style by Louis Sullivan. The cornerstone was laid by President Woodrow Wilson. It served as the first headquarters of the American Federation of Labor (AFL), the largest trade union federation in the U.S. and the forerunner to the modern AFL-CIO. The AFL vacated the structure in 1956 after its merger with the Congress of Industrial Organizations (CIO). The Pipefitters union purchased it. The building is on the National Register of Historic Places, and the facade of the building is being incorporated into the Washington Marriott Marquis as a preservation effort.