Carter changed careers several times in his life and was a prolific writer on topics of religion, mathematics and science.

"Carter became connected with a couple of quack patent medical devices called the "Electropoise" and the "Oxydonor Victory."

These machines were so bogus that they were one of the first products taken to court for mail fraud by the US Postal Service, which eventually won its case against the manufacturers."

Carter played a key role in developing British Israelism's two-seedline doctrine by incorporating a theory on the origin of the serpent's seedline.

Carter believed that "the tremendous pull of the sexual appetite, aroused by the excited state of the woman" caused humanity's fall in the Garden of Eden.

His ideas were initially popularized when they were repeated by C. A. L. Totten (1851–1908) who brought Carter's theories in the mainstream of British Israelism during the 1890s.