Transportation has long played a role in the shaping of East Boston. Clipper ships were built at the shipyard owned by Donald McKay in the mid-19th century. A subway tunnel connecting the neighborhood to the rest of the city opened in 1904 and was the first undersea tunnel of its kind in the United States. Rows of houses were torn down to build the Sumner Tunnel in 1934 and the Callahan Tunnel in 1961, directly connecting automobile traffic from downtown Boston. In the early 1920s, an airfield was built, and eventually it was expanded to become Logan International Airport. The eastern terminus of Interstate 90 (the Massachusetts Turnpike) has been at Route 1A next to Logan Airport since 2003, and the newer Ted Williams Tunnel (1995) links I-90 from East Boston to the rest of the city.