It was the first cookbook by an American author.
You can read and download a PDF version of the book.
The book can be viewed as a success as it was printed, reprinted and even pirated. Have a look at Lucy Emerson’s New England Cookery Book 1808, which is essentially Simmons’ book with a different cover!
While have a look on the website that hosts this PDF version I came across The Historic American Cookbook Project which sounds really interesting. On reading further it is a collection of heritage cookbooks and contains images of heritage cooking utensils and objects held by The Michigan State University Museum. There is a detailed essay of how the project started HERE and it also contains full details of the books within the archive and links to them.
This is a fabulous site and I am so pleased I stumbled across it.