official Bronx County historian from 1989 to 1996, authoring several books about the Bronx. Separation from Manhattan Island After an increase in ship traffic in the 1890s, the United States Army Corps of Engineers determined that a wide canal was needed for a shipping route between the Hudson and Harlem rivers. Such a canal had been proposed since the early 19th century. In the 1810s, a narrow canal had been dug through the south end of Marble Hill at approximately 222nd Street, known as "Boltons' Canal" or "Dyckman Canal". Construction of such a waterway, the Harlem River Ship Channel, finally started in January 1888. The canal was to be in width and had a depth of to . It would be cut directly through the rock of Dyckman's Meadow, making a straight course to the Hudson River. The first section of the canal, the cut at Marble Hill, was completed in 1895 and opened on June 17 of that year. Several festivities including parades were held to commemorate the occasion. This rendered Marble Hill an island bounded by the canal to the south and the original course of the Harlem River to the north. The Greater New York Charter of 1897 designated Marble Hill as part of the Borough of Manhattan. A bridge opened over the former Marble Hill alignment of the creek in 1900, carrying Broadway. The bridge's superstructure was demolished shortly afterward, with the construction of the IRT subway above Broadway in 1904. Effective January 1, 1914, by an act of the New York State Legislature, Bronx County was created, but Marble Hill remained as part of New York County. Later in 1914, the old river was filled in with of landfill, physically connecting Marble Hill to the Bronx and the rest of the North American mainland. Both the King's and Dyckman Free Bridges were covered over with landfill. The bridge carrying Broadway over the former alignment of the creek at 230th Street was destroyed in the late 1920s. At 210 West 230th Street, at the southwest corner with Broadway, is a plaque designating the area as the site of the King's Bridge. The site of the Dyckman Free Bridge is located on the grounds of today's Marble Hill Houses. Character Housing Six-story apartment houses were constructed in the 20th century, and in the early 1950s urban renewal came to the area. A complex was built bounded by