https://www-tc.pbs.org/fmc/book/pdf/ch6.pdf https://www-tc.pbs.org/fmc/book/pdf/ch6.pdf gives 41% in the first decade of the 20th century, quoting the US Censu

https://www-tc.pbs.org/fmc/book/pdf/ch6.pdf https://www-tc.pbs.org/fmc/book/pdf/ch6.pdf gives 41% in the first decade of the 20th century, quoting the US Census Bureau. "Unaffiliated with any church" was the majority position of the US from then until at least 1950, it seems: https://rmadisonj.blogspot.com/2015/03/sunday-mornin-comin-down.html https://rmadisonj.blogspot.com/2015/03/sunday-mornin-comin-d...