In the late 1960s, Texas general contractor H.B. Zachry Co. built a 500-room, 21-story Hilton hotel in downtown San Antonio for the city's HemisFair global exposition, and ended up creating a benchmark in modular construction.
To get the Hilton Palacio del Rio Hotel built by HemisFair's April 1968 start, the contractor—now called Zachry Construction Corp.—built the rooms eight miles off site and placed them in the hotel's steel skeleton. The completed room units included plumbing fixtures, lighting, beds, TVs and even ashtrays. A crane hoisted the modules into place—with stabilizing help from a skid-mounted helicopter rotor—in only 46 days. The entire hotel was built in 202 working days, opening five days early on April 1, 1968.