text: The cornerstone of the first building to be constructed, the Internal Revenue building, was laid by Treasury Secretary Andrew W. Mellon on May 25, 1929. While digging its foundation, workers uncovered a dock which was at least 100 years old. Indiana limestone was used for the facing, and Tennessee marble for the columns. The sites of all the Triangle buildings had been established in their revised positions by May 1929, with two exceptions: The positions of the Justice and Archives buildings remained as originally planned (with Justice in the east), and the apex space remained unallotted. President (and former Commerce Secretary) Herbert Hoover laid the cornerstone of the Commerce building on June 10, 1929, using the same trowel President George Washington had used to lay the cornerstone of the U.S. Capitol. The construction contract for the Commerce building (set at $13.567 million) had been signed in March, and the contract for its limestone facade—according to at least one newspaper account, the largest stone contract in world history—was awarded in April. By then, the cost of the Commerce building had risen to $17.5 million. Due to the formerly marshy condition of the soil and several submerged streams nearby, more than 18,000 pilings had to be set to support the Commerce building. Water pressure from the submerged Tiber Creek made it too difficult to drive the piles, so a deep-sea diver descended into the underground Tiber Creek and drilled a hole 20 feet (6.1 metres) deep into the earth. A hose was inserted into the hole, and water pumped from the earth until the water table dropped and the driving of the piles could be accomplished. The October 1929 stock market crash and subsequent Great Depression led newly elected President Herbert Hoover to increase spending on existing public works as a means of stimulating the economy. No funds had been authorized yet for the Archives, Independent Offices, Justice, or Labor buildings, and Hoover secured an additional $2.5 million a year for 10 years from Congress for this purpose. Work on the Justice and Independent Offices/Labor buildings now proceeded.