There are a few tidbits of information about him - enough to suggest a talented songwriter whose role in the development of American popular song has been consistently underrated, if not outright ignored.
When researching I Went Down to St. James Infirmary, I discovered both where and when he was born. This was not a particularly difficult thing , and reaffirms the general lack of interest in this man. We have yet to discover when he died. One contributer to this site, Andrew Barrett, noted that Grainger renewed the 1926 copyright of a book he co-wrote with his friend Bob Ricketts, How to Sing and Play the Blues Like the Phonograph and Stage Artists, on October 7th, 1954. As a result, one might assume that he was alive in 1954. In 1955 though, a writing partner reportedly renewed the copyright for a song they wrote together, replacing (the now deceased) Porter Grainger's name with his daughter's, Portia Grainger.
This last bit of news, that Porter might have had a daughter, does not necessarily fly in the face of descriptions of Porter Grainger as an openly flamboyant homosexual - but it does give us pause for reflection. The 1930 census lists an Ethel and a Portia Grainger living in New Orleans. Portia was then 5 years old, and her mother 30. It adds that Ethel - although not living with her husband at the time of the census - was married, and had been for 10 years. Ethel Grainger, Howard Rye states in the liner notes to the CD Porter Grainger 1923-1929, recorded under the name Ethel Finnie. Porter played piano on these recordings. I have noted in the book, though, that Grainger claimed (on the 1930 census) that he had been married since he was 33, which would have been around 1924, rather than Ethel's statement of about 1920. Grainger also claimed on his WW1 draft card that he was already married (that is, before 1920), but this could reflect a reluctance to being drafted (having dependents could affect one's priority for the draft). It's slippery, isn't it?
The evidence that Porter had a daughter Portia, as far as I can tell, is not definitive, and we cannot even claim with assurance that (census statements notwithstanding) Porter was ever married. Nor can we claim, aside from some circumstantial commentary, that he was homosexual. If he did not have a daughter Portia, the likelihood increases that he was still alive in 1955, when the copyright on his song was renewed.
I would be delighted to be told that I am incorrect, that we do have more substantiated information about his life.
Correspondent Bob Hutchins wrote to me about a letter his grandmother received in 1948 (see the post above) suggesting that Grainger could have returned to Bowling Green once he made a bit of money. Music historian Elliott Hurwitt notes that we have mostly looked for clues to Grainger's later life elsewhere, in places like New York and Chicago - perhaps Tennessee might serve as a good hunting ground, at least as far as discovering the place and date of Porter Grainger's death.
(ps Andrew Barret sent me a scan of a photograph showing Porter Grainger posing with a large crowd of other musicians/songwriters, including Eubie Blake, James P. Johnson, Jelly Roll Morton and over a dozen others (many unidentified). Morton died in 1941, so the photograph obviously predates that event. Grainger's inclusion in this collection suggests, to me at least, that he was regarded highly in some music circles.)