The five-year waiting period was established in 1954 after an evolutionary process. In 1936 all players were eligible, including active ones. From the 1937 election until the 1945 election, there was no waiting period, so any retired player was eligible, but writers were discouraged from voting for current major leaguers. Since there was no formal rule preventing a writer from casting a ballot for an active player, the scribes did not always comply with the informal guideline; Joe DiMaggio received a vote in 1945, for example. From the 1946 election until the 1954 election, an official one-year waiting period was in effect. (DiMaggio, for example, retired after the 1951 season and was first eligible in the 1953 election.) The modern rule establishing a wait of five years was passed in 1954, although an exception was made for Joe DiMaggio because of his high level of previous support, thus permitting him to be elected within four years of his retirement.

So he wasn’t a first-ballot guy (assuming he was voted upon in 1953 election) but he did beat the current five-year waiting period.