- 1876 to 18791,531
- 1880 to 18841,781
- 1885 to 18892,454
- 1890 to 18943,208
- 1895 to 18992,822
- 1900 to 19043,156
- 19052,142
The preservation of the Duke University Libraries Digital Collections and the Duke Digital Repository programs are supported in part by the Lowell and Eileen Aptman Digital Preservation Fund