The LaSalle Street Tunnel was Chicago's second tunnel under the Chicago River. It was started November 3, 1869, and completed July 4, 1871. It was designed by William Bryson who was the resident engineer for the Washington Street Tunnel. It was 1,890 feet (576m) long, and cost $566,000.
In the 1880s the cable car companies took over the tunnel, and it was used for cable car service until 1906.
The reversing of the Chicago River exposed the tunnel in 1900 and a wider, deeper replacement was built in drydock from steel plate and lowered into a trench in the riverbed. It opened to electric streetcar service in 1911-1912.
The LaSalle Street tunnel was in use until November, 1939, when it was closed during the construction of the Milwaukee-Lake-Dearborn-Congress subway, the Lake & LaSalle (now Clark & Lake) station of which intersected the tunnel's south ramp under Lake Street.
The north entrance ramp toward the tunnel remains in the middle of LaSalle Street, providing access to, and egress from, Caroll Street and the network of lower level streets and parking north of the River.