I remember Stewart's Calculus as a reasonably good textbook. Though they seemed to publish a new edition every two years. Chapter and problem set numbers would get shuffled around, and so you needed the newest edition in order to do assigned homework.
How much has undergraduate level calculus really changed in the last 200 years? The constant updates disrupted the used textbook market and drove sales of new books.
You'd have to come to your own conclusions on the differences though, analyzing math books can take a while. :) The form is quite different.
(I searched "project gutenberg calculus" with no quotes and that was hit #1. The second result appears to come from 1865, so maybe I should have spent just a bit longer with that page.)
Hm, my profs used that textbook, but they were fairly careful not to use questions from it for graded homework. This let you use old versions for studying, without an impact on your grades.
How much has undergraduate level calculus really changed in the last 200 years? The constant updates disrupted the used textbook market and drove sales of new books.