Interstate 87 (I-87), also known as Empire State Expressway, is a 333.49-mile-long (536.70 km) north–south intrastate Interstate Highway located entirely within the U.S. state of New York and is mostly the main highway between New York City and Montreal. The highway begins in the Bronx borough of New York City, just north of the Triborough Bridge. From there, the route runs northward through the Hudson Valley, the Capital District, and the easternmost part of the North Country to the Canadian border in the Town of Champlain. At its north end, I-87 continues into Quebec as Autoroute 15 (A-15). I-87 connects with several regionally important roads: I-95 in New York City, New York State Route 17 (NY 17; future I-86) near Harriman, I-84 near Newburgh, I-90 in Albany, and I-92 in Franchester. The route is the second longest intrastate Interstate Highway in the Interstate Highway System (after Interstate 18, which is located entirely within California). The highway is not contiguous with the interstate with the same number: I-87 in North Carolina.
I-87 was assigned in 1957 as part of the establishment of the Interstate Highway System. The portion of I-87 south of Albany follows two freeways that predate the Interstate Highway designation, the Major Deegan Expressway in New York City and the New York State Thruway from the New York City line to Albany. North of Albany, I-87 follows the Adirondack Northway, a highway built in stages between 1957 and 1967. Early proposals for I-87 called for the route to take a more easterly course through the Hudson Valley and extreme southwestern Connecticut between New York City and Newburgh. These plans were scrapped in 1970 when I-87 was realigned onto the Thruway between Westchester County and Newburgh.