<P> Building the locks began with the first concrete laid at Gatun on August 24, 1909 . The Gatun locks are built into a cutting into a hill bordering the lake, requiring the excavation of 3,800,000 m (4,970,212 cu yd) of material (mostly rock). The locks were made of 1,564,400 m (2,046,158 cu yd) of concrete, with an extensive system of electric railways and cable cars transporting concrete to the lock - construction sites . </P> <P> The Pacific - side locks were finished first: the single flight at Pedro Miguel in 1911, and Miraflores in May 1913 . The seagoing tugboat Gatun, an Atlantic - entrance tug used to haul barges, traversed the Gatun locks on September 26, 1913 . The trip was successful, although the valves were controlled manually; the central control board was not yet ready . </P> <P> On October 10, 1913, the dike at Gamboa which had kept the Culebra Cut isolated from Gatun Lake was demolished; the detonation was made telegraphically by President Woodrow Wilson in Washington . On January 7, 1914, the Alexandre La Valley, an old French crane boat, became the first ship to make a complete transit of the Panama Canal under its own steam after working its way across during the final stages of construction . </P> <P> As construction wound down, the canal team began to disperse . Thousands of workers were laid off, and entire towns were disassembled or demolished . Chief sanitary officer William C. Gorgas, who left to fight pneumonia in the South African gold mines, became surgeon general of the Army . On April 1, 1914 the Isthmian Canal Commission disbanded, and the zone was governed by a Canal Zone Governor; the first governor was George Washington Goethals . </P>

Who was president when the panama canal opened