Construction of the Erie Canal, hailed as the greatest engineering accomplishment to that time, began under the leadership of Governor De Witt Clinton on July 4, 1817. With little technical knowledge, thousands of workers surveyed, blasted, and dug a 363-mile canal across the state. They hewed through solid rock and dug in marshes, erected aqueducts to carry the canal over rivers and valleys, and built 83 locks to take the canal over changes in ground level. When completed in October, 1825, the Erie connected Albany and Buffalo and became the main route between the Atlantic Ocean and the Great Lakes. Passenger and freight barges crowded the canal, Western New York flourished with new, cheap transportation, and the Erie Canal hastened development of the Mid-West. Its success stimulated enlargement of the original canal in the 1840's and construction of additional canals, and more than 500 miles of canals connected the Erie to other sections of New York State. After the 1870's, canal transportation declined and many canals closed. The Erie was modernized in 1918 as part of the State Barge Canal System consisting of the Erie, Champlain, Oswego and Cayuga-Seneca Canals.