He was a historical romance fiction writer in the early half of the 19th century. He's said to have written over a 100 novels and 67 of them are catalogued in the British Museum. He began writing at an opportune time after Sir Walter Scott had done a lot to make the genre popular as well as Alexandre Dumas.
If you would like to read further about James here's a link to a great online source.
You can also read some of his books at google books, just search the author's name. You'll need to go to the second page of the search before you find some of his titles.
I find it interesting to read about and read some of the works of authors who came before us. I hope you'll enjoy it too.