Construction of the Erie Canal, begun on July 4, 1817, under the leadership of Governor De Witt Clinton, was hailed as the greatest engineering accomplishment to that time. With little technical knowledge, thousands of workers surveyed, blasted, and dug a 563-mile canal across the state, hewing through solid rock, digging in marshes, erecting aqueducts to carry the canal over rivers and valleys, and building 83 locks to take it over changes in ground level. Completed in October, 1825, it 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 canal also hastened development of the Mid-West. Its success stimulated enlargement of the original canal in the 1840's and construction of additional canals, so that more than 500 miles of canals connected it to other sections of New York State. After the 1870's, canal transportation declined and many canals closed, but the Erie was modernized in 1918 as part of the State Barge Canal System consisting of the Erie, Champlain, Oswego and Cayuga-Seneca Canals.