Top: Such is Life, October 17, 1924. Middle: Uncle Wiggily, September 6, 1925. Bottom: Animal Town, October 18, 1923. Click to enlarge.
You can't work comic world in-jokes into your strips if you don't know your comics history.
For many of us, comics history is EC Comics, Dick Tracy and Robert Crumb.
But there's work from 1890 - 1930 that doesn't get much showing. A site called Barnacle Press is collecting and displaying obscurities from this era. It's fascinating to see what the papers were printing, but a lot of it is not highly readable or entertaining. Every cartoonist should have a general familiarity with this vintage but should realize the material is often weak and remains obscure for a reason.
Closely related is Stripper's Guide, blog of newspaper strip historian Allan Holtz. The blog seems intended particularly for Holtz's colleagues as they attempt to compile an archive of every American newspaper strip. And they're well along. This is no half-hearted effort.
All this old stuff is worth an occasional browse. It depends on your mood whether you'll find it charming and pioneering or naive and illegible.