The Lamar Hunt U.S. Open Cup final highlights a busy week for MLS clubs as the Philadelphia Union play host to the Seattle Sounders FC on Tuesday, September 16 at 7:30 p.m. ET (GolTV). The greater Philadelphia area has a rich history in the U.S. Open Cup – something the Union will hope to build on. In the 20th century, the Bethlehem Steel and Philadelphia Tridents of the American Soccer League each won multiple finals. A win on Tuesday would be the first trophy in franchise history for the Union. The Sounders, on the other hand, have reached the final in five of the last six years and have won three (2009, 2010, and 2011).