Neslen was raised in Salt Lake City. From 1902 to 1904 he was a Mormon missionary in Germany. During his mission, most Mormon missionaries were banished from Germany and he was imprisoned in Danzig. He served as president of the KönigsbergDistrict of the LDS Church for a part of his mission.
Neslen was a member of the Democratic Party and a delegate to the Democratic National Convention in 1912.
Neslen worked a total of 15 years for the Deseret News. He was also a realtor and for a time served as secretary of the Salt Lake Real Estate Association.
On October 26, 1905, Neslen married Grace T. Cannon, a daughter of George Q. Cannon. They had five children.[3] Following the death of Grace on June 20, 1950, Nelsen married Julia Paxman Sloan.[1]
Neslen's half-sister, Florence Neslen, was the mother of Richard L. Evans, an apostle in the LDS Church.
