The history is generally accurate, except for minor details. 403(b)s began in
1958, as noted in the accompanying NYTimes article (link is at end of article, or
here).
It's true that Section 40
1(k) of the IRC wasn't enacted until
1978 (and didn't become effective until
1980), but 40
1(k)s are just "Cash Or Deferred Arrangement" (CODA) plans.
According to ICI, these go back to the
1950s (with IRS rulings in
1956 to regulate them). The profit sharing (employer contribution) portion of these plans goes all the way back to the beginning of the modern income tax (
19
13), i.e. not counting the income tax that Lincoln instituted.
Similarly, there were
annuity plans for educators predating Section 403(b) of the IRC, going all the way back to the founding of the Teachers Insurance and Annuity Association (TIAA) in
19
18.
The NYTimes article cited above confirms that mutual funds were added to 403(b)s in
1974. But that's for "real"
1940 Act mutual funds. Remembering that 403(b)s were created as annuities, we can also consider variable annuities (i.e. similar to mutual funds, but contained inside annuity wrappers). The first variable annuity was the College Retirement Equities Fund (CREF),
created in 1952.
IMHO, if one wants to talk about the full history, one goes all the way back to the
19
10s. If one wants to talk about the modern regulatory era, one starts in
1974 with ERISA.