 Routes 2 and 25 were realigned slightly on March 1, 1921, to utilize the modern US 9 corridor from Croton-on-Hudson to Peekskill and from Saratoga Springs to South Glens Falls, respectively.When the first set of posted routes in New York were assigned in 1924, the general routing of modern US 9 was designated as New York State Route 6, which went from the New York City line at Yonkers north to the Canadian border near Rouses Point.From New York City, NY 6 followed current US 9 north to Tarrytown, where it joined legislative Route 2 and continued north through Valatie to Albany via legislative Routes 1 and 2.