Adams was graduated from the gymnasium with an enviable record just prior to leaving the Old World.
Soon after arrival in the United States he enlisted in a Massachusetts regiment and continued in service through the war, being twice wounded in battle. He then went west, joined the 3d United States Cavalry, and served two years against the Kiowa and Comanche Indians in New Mexico and Texas.
In 1870 he was appointed brigadier-general of the Colorado militia by Governor McCook and was subsequently appointed Ute Indian Agent upon recommendation of the same official.
Arriving at the Agency in June 1872, Adams and his wife found the Utes uneasy and fearful of attack, as reports were being circulated of Indian outrages. He succeeded in dispelling their suspicions and won their confidence. Soon he had a saw-mill running, hay being cured, their cattle cared for, and as winter approached he inaugurated a little school.
In 1874 he resigned from the Indian service to become post-office inspector. When the Ute uprising of September 29, 1879 resulted in the murder of Agent Meeker and his employees and the captivity of the white women, an emergency existed which called for a man of tact and of acknowledged influence among the Indians. Adams was called upon by the government. He proceeded immediately to the scene of hostilities and in cooperation with Chief Ouray secured the release of the white women. As one of a commission of three he investigated the tragedy and obtained the surrender of some of the leaders for trial. A delegation of Utes was then escorted to Washington, where they were induced to sign a treaty surrendering their land in Colorado and agreeing to remove to a reservation in Utah.
President Hayes appointed Adams in 1880 minister to Bolivia. War then existed between Bolivia and Chile, and Adams acted as an arbitrator on the part of the United States in the conferences at Arica.
In 1882 he left Bolivia and again became a post-office inspector. From this position President Cleveland removed him in 1885 for "offensive partisanship. "
Thereafter he engaged in business in Colorado, being interested in mining, glass manufacture, and mineral-water development. He met his death in an explosion at the Gumry Hotel, Denver.
Adams was married to Mrs. Margaret Thompson Phelps, a sister of the wife of Governor McCook. It was at her instance that his name was changed.