There are yards and yards of discussion regarding this song. Welcome to Mudcat! One of the first things you'll want to learn here is to use the Search feature (upper left corner), then you can read up on the topic and ask your questions or add remarks in existing threads.

Enter "Streets of Laredo" or "Saint James Infirmary Blues" into the search box and you will have lots of material regarding the sources and authenticity of the various stories about the song.

Here are a few (and look at the top of each thread for linked discussions):

. . . all wrapped in white linen

Tune Req: St. James Infirmary Blues

The Unfortunate Rake

An article posted by a member about the history of the song