Nelson C. Simonson was born in in Detroit, Michigan and grew up in New York City. He served in the United States Navy, 1944-74. While in the Navy he attended Cornell University, the University of Rochester (B.S. in Mechanical Engineering), and Rensselaer Polytechnic Institute (Bachelor of Civil Engineering). He then worked in the Navy's Civil Engineer Corps.
Simonson joined the Unitarian Church of the Larger Fellowship in the 1950s. Since then he has attended Channing Memorial Church in Newport, Rhode Island and the Unitarian Church of Arlington, Virginia. On retiring from the Navy, he moved to Reading, Pennsylvania and took a job with a large engineering firm. There he joined the historic First Unitarian Universalist Church of Berks County, Reading, Pennsylvania and "fell in love with" the history and theology of Universalism. He has been on the board of the Joseph Priestley District, a president of the Pennsylvania Universalist Convention, and on the board of the Murray Grove Association.
Nelson and his wife Caroline have five children, eight grandchildren, and three great grandchildren. He is now fully retired and lives in a community run by the United Church of Christ outside of Reading, Pennsylvania.