- 1851 to 18541,332
- 1855 to 18591,513
- 1860 to 18643,307
- 1865 to 18692,635
- 1870 to 18741,943
- 1875 to 18791,785
- 1880 to 18841,794
- 1885 to 18892,466
- 1890 to 18943,235
- 1895 to 18993,280
- 1900 to 19043,309
- 1905 to 19093,215
- 1910 to 19143,843
- 19152,578
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