Excavation of the foundation was complete by the end of June 1915. Concrete foundations had also been laid and cured, and most of the brick foundation was in place as well. Most of the amphitheater's foundation was complete by June 30, 1916. The foundation included 629,000 bricks, of structural steel, and of marble (for the exterior of the structure). The Guastavino tile system, patented in 1885, was used to create arches and vaults in the basement. More than of this tile were used. The heating, clean water, and sewage systems were also complete. The Corps of Engineers also finished the architectural drawings for the approaches around the amphitheater as well, and was ready to start work on them.