Abraham Lincoln never had an ice cream sundae. Neither, for that matter, did Dolley Madison.
Ice cream sundaes did not exist until the 1890s.
This *is so* a fascinating fact related to *The Secrets of Mary Bowser,* on account of Mary not being able to go out for an ice cream sundae that did not yet exist. You may set a scene in an ice cream emporium in the 1850s, but you do not want to fudge the historical accuracy by having anyone order a sundae.
Ha ha, get it? "Fudge"!