Complex sentence: Philadelphia had not seen any residential high-rise development since the 1980s, and The St. James was one of the first to begin construction in the city, preceded only by the 16-story Residences at the Dockside, which broke ground in 2000.
Split into simpler sentences: Philadelphia had not seen any residential high-rise development since the 1980s, and The St. James was one of the first to begin construction in the city. The only high-rise project to begin earlier was the 16-story Residences at the Dockside, which began in 2000.