There are at least 3 general types of poker chip edges (round, square and semi-round), and all three types go way back. I have a Kernan poker chip catalog from about 1900 that advertises both "round" and "square" edged INLAID chips by those very names.
Here are some pictures from the catalog. I'd sell photocopies of all the pages from the catalog for $11 total. This catalog is the only old one that I know of that is devoted just to poker chips.

If you look at the catalog reproductions at the end of Seymour's book, you will see circa 1900 catalogs offering round, square- and semi-round and square edge inlaid chips. I suspect the round edged ones were mainly for poker games and the square for house games for quick and steady stacking and cutting/counting.

Robert