Annual reviews covering English literatures broadly, including British, American, Canadian, etc.

1919-present, available via Oxford Journals Online.

Annual reviews of scholarship on American authors.

2000-present available via e-Duke Journals
1998-present available via Project Muse

1991-present are available online.

Is there a journal devoted to your author, or to the type of literary study your are pursuing? If so, then look to see if there is an issue which provides an annual overview of research.