As a retired attorney who spent much of his career working with tax exempt organizations, I would like to point out the the correct citation is §501(c)(3) of the Internal Revenue Code of 1986. That designation was put in place in or a bit after 1918 and remains the same to this day except that the date of the Code has been revised whenever there has been a major revision. That designation was certainly used in the Internal Revenue Code of 1939.
