In 1894, Edge was elected to the executive committee of the Atlantic City Republican Party. From 1897 until 1899 he served as journal clerk of the New Jersey Senate, a position that enabled him to meet state political figures and learn parliamentary procedures. In the 1890s Edge was a sergeant with the Morris Guards, a private military organization based in Atlantic City, and when the Spanish–American War began in 1898, he volunteered the company for service in the United States Army. He was commissioned as a second lieutenant in the Army during the war and served for a few months, but did not leave the United States. Between 1901 and 1904, Edge was appointed secretary of the state senate, another position that enabled him to cultivate relationships with state legislators.
