The New England Journal of Medicine has provided free electronic access to their content, back to the first article in the year 1812. According to their website:
"The more recent part of the archive from 1945 through 1989 is presented in an HTML format similar to that used for current issues, with full text, tables and figures, PDFs, and tables of contents. The older archive from 1812 through 1944 contains tables of contents plus PDFs of individual articles. The entire archive is fully searchable. This is possible because every page of the Journal was first scanned, using high-resolution technology to produce PDF files, which were then read, using optical character recognition, to produce the HTML. Tagging and indexing according to specialty were done by computer algorithm and Medline tags as far back as they were available. These processes are not perfect, and readers may find some errors that have been missed, especially in the older content. The entire archive consists of 8498 issues with 486,434 pages and 145,969 articles with 75,649 images.
Click here to have a look at the index.