Hi, Kimberly-
Well, the Cooperative Recreation Service had hundreds, maybe thousands of songs in their catalog. Most are still available from World Around Songs, successor to Coop Rec Svc. These organizations sold (and still sell) their own songbooks, but also have offered to make custom songbooks for various groups - it's seen these songbooks for Scout groups, churches, the YWCA, and the American Camping Association. I believe there was an option to add songs not in the Cooperative Recreation Service catalog.
Methodists cover a wide spectrum. I know a Methodist church here in California that performs gay marriages, and the Folklore Society of Greater Washington has an annual "Getaway" at a Methodist camp that prohibits alcohol. When I was a kid in the 1950's, it was common for Methodist congregations to frown on drinking, dancing, and playing cards. As stated on this page (click) the town of Ocean Grove on the Jersey Shore was founded as a Methodist meeting retreat center in the 1869. The town once had very strict rules of conduct for visitors, including regulating the modesty of "bathing costumes." [Click here for more information - Ocean Grove really is interesting.] Now that they are the United Methodists, the rules are quite relaxed - perhaps scandalously so, in the mind of old-timers.
But as for the songbook, most likely the songs were chosen by church representatives from the large catalog of the Cooperative Recreation Service.

-Joe-