- Schley, Mrs. M. H. (1858) July 6.
- Scott, J. Parkin. 1843 Oct. 19; 1846 Jan. 5; 1851 Dec. 13; 1857 Feb. 18.
- Seabrook, E. M. 1852 Nov. 23.
- Sears, E. J. 1858 Nov. 5.
- Seavy, S. S. 1843 Jan. 10.
- Sedwith, Richard F. 1845 Feb. 14.
- Seidenbush, O.S.B., Father F. Rupert. 1860 Oct. 1.
- Semmes, Thomas J. 1855 Feb. 5, March 5.
- Sennott, George. 1863 Oct. 15.
- Sestini, S.J., Father Benedict. 1873 Dec. 6.
- Seton, Elizabeth. 1866 Feb. 20; 1870 Dec. 22; 1873 Dec. 23; 1875 Jan. 12.
- Seton, William. (1871?) April 4; 1871 Nov. 19; 1872 Feb. 28, March 9, June 9; 1874 March 4, Aug. 17, Oct. 31; 1876 April 9.
- Seton, William, Jr. 1860 Oct. 4.
- Severance, George. 1862 March 22; 1874 Nov. 30 (to Frederick R. Pustet, enclosed in F. R. Pustet to O.A.B.), Dec. 28.
- Shackford, C. C. 1862 Jan. 11.
- Shafer, P. W. 1852 Dec. 20.
- Sharon, Joseph. 1845 Dec. 24.
- Shaw, Abner. 1843 Jan. 11.
- Shaw, J. Coolidge. 1845 Oct. 14.
- Shaw, Libby. 1864 Jan. 29.
- Shea, John G. 1864 Sept.
- Shea, S.J., Father Joseph. 1870 June 16.
- Shennan, Ellen Boyle Ewing. 1858 May 4; 1862 March 13; 1872 Jan. 30 (to Madeleine Vinton Dahlgren, enclosed in 1872 Jan. 30, M. V. Dahl gren to O.A.B.), Feb. 21; 1873 Feb. 6; 1874 Dec. 8; 1875 Jan. 4, Sept. 28.
- Sibley, George E. 1869 June 1.
- Sibley, John Langdon. 1862 Oct. 27; 1873 April 8.
- Simplicia, Sister. 1870 Oct. 7, Oct. 29, Dec. 2.
- Simpson, Richard. 1853 April 4 (to Father Hecker); 1862 July 4.
- Slack, Charles W. 1844 June 10.
- Slade, Charles. 1852 Dec. 5.
- Smalley, E. Marvin. 1859 Nov. 5.
- Smarius, S.J., Father C. F. 1858 Sept. 24, Oct. 13; 1860 Nov. 5.
- Smeddinck, Father B. 1861 Aug. 18.
- Smith, Abby Parker. (1844?) May 7; 1845 Dec. 21; 1847 May 31; 1853 May 9.
- Smith, Anna E. 1872 Nov. 1.
- Smith, E. S. 1857 Oct. 23.
- Smith, J. C. 1844 Nov. 14.
- Smith, Lorenzo. Undated.
- Smith, Marshall. 1861 Nov. 10.
- Smith, T. G. 1858 March 28.
- Smith & Co., John Dillon. 1844 Nov. 28.
- Sophopoiana Society of the College of St. Joseph. 1850 Nov. 15.
- Sorin, C.S.C., Father Edward. 1851 May 13; 1854 May 14; 1865 Oct. 12, Nov. 7, Nov. 11, Dec. 3, Dec. 5, Dec. 6, Dec. 15, (Dec. 21); 1866 Feb. 3, April 8, May 2, June 5, July 1, Nov. 3, Dec. 29; 1867 Jan. 10, Nov. 11; 1868 Jan. 14, May 12, Oct. 21; 1869 Aug. 9; 1872 May 13.
- Sourin, Father Edward J. 1850 Jan. 29; 1851 April 15; Undated.
- Spalding, Father John L. 1874 Jan. 14.
- Spalding, James R. 1856 Sept. 20.
- Spalding, Father Martin J. 1844 Nov. 21; 1853 Nov. 15; 1857 Oct. 15, Nov. 19; 1858 Feb. 16.
- Spellissy, Father James M. 1872 Dec. 21.
- Spooner, Mary Ann. 1866 Oct. 31.
- Spottiswoode, John. 1857 Sept. 2.
- Staff, John J. 1858 April 2().
- Staff Officers of Major General Winfield S. Hancock. 1864 Aug. 29.
- Stafford, Father M. 1867 July 11.
- Stanton, Edwin M. 1863 March 29, May 28.
- Starr, Eliza Allen. 1864 Oct. 31; Un dated.
- Stearns, Sarah F. (1847?) Feb. 17, Dec. 19; (1848) Dec. 7; 3 Undated.
- Steisbuck, C. C. 1862 July 14.
- Sterry Zuut, Th. 1856 March 18.
- Stewart, Lemuel L. 1845 Jan. 22.
- Stokes, Father Joseph. 1846 Dec. 21; 1848 Jan. 24.
- Stokes, T. J. P. 1858 Nov. 11.
- Stokes, William A. 1845 Jan. 2, March 5; 1846 March 13, April 24; 1849 May 9; 1852 Jan. 26; 1857 Dec. 20; 1859 Oct. 27; Undated.
- Stone, James Kent. 1870 May 27.
- Stone, James M. 1861 Dec. 20, Dec. 28, Dec. 30; 1862 Jan. 2, Jan. 8 (to Edward P. Brownson).
- Stores, J. P. B. 1843 Oct. 19.
- Strain, Father Patrick. Undated.
- Strong, H. W. 1846 Dec. 22.
- Stuart, Charles E. 1857 Nov. 20, Dec. 27, Dec. 29; 1858 Jan. 2, March 1, April 26.
- Stuart, Emily Mary. 1858.
- "Studiosus Rerum." 1875 (Aug. 28).
- Sturgis, William. 1843 Oct. 6.
- Sullivan, Father John T. 1860 Dec. 27; 1862 Jan. 20; 1873 Jan. 6, Jan. 22.
- Sumner, Henry. 1844 June 28; 1 845 Jan. 21; 1866 June 26, July 9.
- Sumner, Charles. 1862 Feb. 2, May 25, July 20, Sept. 1, Oct. 12; 1863 Jan. 4, April 7, Oct. 5, Dec. 27; 1864 March 22.
- Sumner, S.J., Father John S. 1869 Nov. 10 (to Dennis & James Sadlier & Co.).
- Sweet, G. H. 1843 Nov. 2, Nov. 14.
- Swen, Brewer and Tileston. 1860 April 23.
- Swinton, W. (186?).
- Synnott, Father Thomas J. 1869 June 8.
- Szedlcik. 1853 June 18.
- Taft, S. K. 1858 Oct. 9.
- Taney, Joseph. 1856 Dec. 29 (to James McMaster).
- Tasker, John T. 1844 Aug. 15.
- Taylor, James H. N. (1843 ?).
- Tefft, B. F. 1842 Dec. 9.
- Tefft, Charles E. 1845 July 21.
- Tellier, Father Remigius J. 1841 Aug. 19; 1860 April 1.
- Tenney, Jessie. 1875 Dec. 5; 1876 Feb. 9.
- Tenney, Jona. 1843 July 27.
- Tenney, Sarah Brownson. (1874); (1874 April?); (1874 June); 1875 Nov. 13, Dec. 2, Dec. 24; 1876 March 12.
- Thébaud S.J., Father August J. 1848 July 7; 1850 July 17, Oct. 30; 1873 Oct. 13.
- Thien, Father Herbert. 1873 April 28.
- Thisse, Father J. N. 1854 Dec. 6; 1859 Jan. 3.
- Thomas,Seth J. (186?) June30.
- Thompson, D. P. 1844 March 10.
- Thompson, George W. 1839 July 26; 1840 Jan. 16; 1843 Dec. 11; 1845 Aug. 25; 1853 Jan.; 1857 Dec. 19; 1858 Feb. 28; 1860 Oct. 22; 1861 Feb. 4, Oct. 11; 1864 Jan. 2; 1865 Dec. 25.
- Thompson, Zadock. 1843 Aug. 12.
- Thoreau, Henry D. 1837 Dec. 30.
- Trembley, Nellie A. 1875 Aug. 6, Aug. 19.