where did the steel for the empire state building come from
Pittsburgh
title: Empire State Building text: project was the largest-ever single order of steel at the time, comprising more steel than was ordered for the Chrysler Building and 40 Wall Street combined. According to historian John Tauranac, building materials were sourced from numerous, and distant, sources with "limestone from Indiana, steel girders from Pittsburgh, cement and mortar from upper New York State, marble from Italy, France, and England, wood from northern and Pacific Coast forests, [and] hardware from New England." The facade, too, used a variety of material, most prominently Indiana limestone but also Swedish black granite, terracotta, and brick. By June 20, the skyscraper's supporting title: Empire State Building text: the levels were still undergoing final approval, with several orders placed within an hour of a plan being finalized. On September 10, as steelwork was nearing completion, Smith laid the building's cornerstone during a ceremony attended by thousands. The stone contained a box with contemporary artifacts including the previous day's "New York Times", a U.S. currency set containing all denominations of notes and coins minted in 1930, a history of the site and building, and photographs of the people involved in construction. The steel structure was topped out at on September 19, twelve days ahead of schedule and 23 weeks title: Empire State Building text: delivered; they would support a combined when the building was finished. The structural steel was pre-ordered and pre-fabricated in anticipation of a revision to the city's building code that would have allowed the Empire State Building's structural steel to carry , up from , thus reducing the amount of steel needed for the building. Although the 18,000-psi regulation had been safely enacted in other cities, Mayor Jimmy Walker did not sign the new codes into law until March 26, 1930, just before construction was due to commence. The first steel framework was installed on April 1, 1930. From there, construction title: Empire State Building text: concrete footings that would support the steelwork. Excavation was nearly complete by early March, and construction on the building itself started on March 17, with the builders placing the first steel columns on the completed footings before the rest of the footings had been finished. Around this time, Lamb held a press conference on the building plans. He described the reflective steel panels parallel to the windows, the large-block Indiana Limestone facade that was slightly more expensive than smaller bricks, and the tower's lines and rise. Four colossal columns, intended for installation in the center of the building site, were title: Empire State Building text: inside the building ensured that materials would be able to ascend quickly and without endangering or inconveniencing the public. At one point, over 200 trucks made material deliveries at the building site every day. A series of relay and erection derricks, placed on platforms erected near the building, lifted the steel from the trucks below and installed the beams at the appropriate locations. The Empire State Building was structurally completed on April 11, 1931, twelve days ahead of schedule and 410 days after construction commenced. Al Smith shot the final rivet, which was made of solid gold. The project involved