[1][2][3] He attended the public schools of Brooklyn, and was a student at New York University for two years as a member of the class of 1881.

[5] Ridgway became a specialist in the use of coastal artillery for harbor defenses, a major strategic concern for the United States government in the late 1800s and early 1900s as the expansion of several nations' navies detracted from the natural defenses America enjoyed because of its location between the Atlantic and Pacific Oceans.

[5] From May 1886 to October 1887, Ridgway was assigned as professor of military science at St. Paul's School in Garden City.

[5] At the start of the Spanish–American War, Ridgway was assigned to assist in the rapid improvement of coastal defenses in the eastern United States.

[5] He was then transferred to Light Battery F, 5th Artillery, which he commanded when it served in the Philippines during the Philippine–American War and in China during the U.S. response to the Boxer Rebellion.

[5] After becoming a colonel, Ridgway was assigned to Fort Barrancas, Florida as commander of the Coast Defenses of Pensacola.

[5] He commanded the Coast Defenses of Boston beginning in November 1915, and remained in this position during the early stages of U.S. involvement in World War I.

[5] In February 1919, Ridgway was assigned to command the Coast Defenses of Oahu, where he remained until retiring in October 1919.

[5] Ridgway was visiting a laboratory in January 1912 when an explosion occurred, which resulted in him losing sight in one eye.