The first canal engineers came from England, Wales, or Holland, and by the late 1790's these European engineers had trained a small cadre of engineers, mostly in the New York area. New York engineers then designed canals and trained younger engineers who spread through Pennsylvania and Ohio. By 1860 there were more than 4000 miles of canals in the United States, mostly dug by immigrants, many of whom were Irish. Irish immigrants did most of the physical labor: in 1818 more than 3,000 Irish laborers worked on the Erie Canal, and by 1826 around 5,000 were working on four separate canal projects. One journalist remarked that alongside water-power and steam-power, 'Irish-power' worked hardest of all. Many people were prejudiced against the Irish, and in the South they were sometimes considered less valuable than slaves. Cheap Irish labor later gave way to cheap Chinese labor even as canals gave way to railroads.