Ammon Ashford Hennacy was born in 1893 in Negley, Ohio. Hennacy was the quintessential man of change. He attended three higher educational institutions in three years (1914-1917), viz., Hiram College, the University of Wisconsin, and Ohio State University. As a teenager Ammon became interested in politics and considered himself a Democrat until 1910 when he became a member of the Socialist party. Hennacy was affiliated with the Baptist church which he disavowed upon declaring himself an atheist. When the United States entered World War I in 1917, Ammon commenced his initial anti-war activities in Columbus Ohio as a draft-resister and a leader of the Young Men's Anti-Militarist League. Not then a pacifist, he was an advocate of the cause of revolutionary socialism. Due to his refusal to serve in the armed forces and fight in a "capitalist war", Ammon was imprisoned in a federal penitentiary for two years (1917-1919). This incarceration experience transformed his thoughts about religion and the use of violence. Contact with and exposure to the person, writings, and ideas of three individuals influenced Hennacy's world view. These individuals were the anarchist Alexander Berkman, the Christian anarchist Leo Tolstoy, and Jesus Christ. During these years, Ammon identified himself as a Christian anarchist, changed his drinking and eating habits, became a teetotaler, adopted a vegetarian diet, and engaged in the practice of fasting. On Christmas Eve 1919, Hennacy and Selma Melms committed themselves to a common law partnership.

While living in New York City in the early 1920s, Ammon resumed his ideological travels becoming a member of the Industrial Workers of the World and joining the Communist party. He affiliated with the Reds not because he had embraced Marxism, but because he had considerable respect for one of the party's leaders. Subsequently, he and his wife spent four years touring the entire United States as propagandists for the Communist party. Hennacy taught American history classes in Alabama and in California where he left the party in 1925. On his birthday in 1925 Ammon and Selma established residence in Milwaukee where he lived until 1942. On the eve of World War II, Selma and her two daughters, Carmen and Sharon, moved to New York City and a marital estrangement ensued. The marriage was dissolved in 1944 and a year later Hennacy exchanged marriage vows with Joan Thomas. With the entry of the United States in World War II in 1941, Ammon became involved in anti-war activities refusing to register for the draft and to pay federal income taxes which would support the conduct of the war. Unlike 1917, he was not arrested. It should be noted that Hennacy never paid federal income taxes from 1943 to 1970.

His long association and friendship with Dorothy Day, a well-known Christian anarchist and pacifist and editor of the "Catholic Worker", was instrumental in Ammon's renewed religious peregrinations. In 1952 with Day as a sponsor, Hennacy was baptized into the Roman Catholic Church. An anarchist priest, one of several priests who befriended Ammon, officiated at the ceremonies. Hennacy's gradual disenchantment with Catholicism led to his departure from the church in 1965 when he proclaimed himself to be a non-affiliated Christian. Ostensibly, Hennacy's social conscience and ideological conviction induced him to establish the Joseph Hill House of Hospitality and St. Joseph's Refuge in 1961 in Salt Lake City. Ammon collected food from Salt Lake City grocers and provided three free meals daily as well as shelter to transients and to the homeless. Donations from the community and Hennacy's friends throughout the United States were welcomed. Only two rules governed the Hill House, viz., no alcohol consumption and no police presence. Instead of being asked to sing religious songs and participate in prayer meetings, the residents were asked to attend Friday night gatherings where Ammon discussed the core beliefs of Christian anarchism and pacifism. The Joe Hill House of Hospitality operated for seven years until the local authorities compelled Hennacy to close it in 1968.

At this point mention should be made of Hennacy's diverse occupational history. Ammon peddled newspapers, cornflakes, soap, aluminum ware and apples, washed pots and pans, was a newspaper reporter, served as a pension league secretary, was employed as a carpenter, sold Fuller brushes, taught high school, worked as a county social worker, drove a milk wagon, labored as an agricultural and dairy farm worker, and directed the Joseph Hill House of Hospitality. While he changed jobs frequently, he also lived in several urban and rural communities residing in Columbus, New York City, Boston, Atlanta, Mobile, Berkeley, Milwaukee, Denver, Albuquerque, Phoenix, and Salt Lake City.

A man of thought and of action, Hennacy manifested his interests and creativity in a variety of ways. Ammon wrote poetry, composed five pacifist plays, penned a novel, and published numerous journal articles as well as three books. In addition to presenting hundreds of pacifist and anarchist speeches before university and church audiences, he was a union organizer, a strike leader, a Sunday school teacher, a conscientious objector, an anti-war demonstrator, a protestor against civil defense, an anti-tax proponent, an opponent of capital punishment, an advocate of the banning of nuclear tests and of bacteriological warfare, a perennial faster seeking penance for the U.S. atomic bombing of Japan, and an ubiquitous picketer. Hennacy commenced his publication career in 1929 when an article appeared in an anarchist periodical. Throughout the 1930s and 1940s, Ammon's work was published in "The Road to Freedom", "Green International Bulletin", "Catholic Worker", "Man!", "The Catholic C.O.", "Individual Action", and the "Industrial Worker. In 1954 Catholic Worker Books printed Hennacy's "Autobiography of a Catholic Anarchist" which served as the basis for an up-dated 1965 version Titled "The Book of Ammon". Shortly before his death on 14 January 1970, "The One-Man Revolution in America" reached the reading public. Joan Thomas's memories of life with Ammon were recounted in her 1974 "biography" of Hennacy which was called "The Years of Grief and Laughter".