Staten Island Midland Railway Co. - incorporated 1907, acquiring the Staten Island Midland Railroad, which in 1890 had succeeded the Richmond County Railroad.
Staten Island Traction Co. - operated by Staten Island Midland Railway Co., renamed from Port Richmond & Prohibition Park Electric Railroad.
In 1920, the Staten Island Midland Railway Co. failed, and the New York City Department of Plant and Structures took over operation. In 1927, these operations were replaced with buses operated by the Tompkins Bus Corp.
In 1925, the Richmond Light & Railroad Co. formed a bus subsidiary, the Staten Island Coach Co. And in 1927, the Richmond Light & Railroad Co. was restructured, with the street railway company named Richmond Railways. The Staten Island Coach Co. never received authority to operate buses until 1933, when it began replacing the Richmond Railways streetcars. In 1934, the final streetcars were replaced with buses.
From 1924 to 1937, Richmond Railways was affiliated with Associated Gas & Electric Co.