M. D. McAlister to Thomas Lincoln Casey, March 8, 1869

M. H. Rassiter to Thomas Lincoln Casey, December 21, 1887

M. H. Rossilin to Thomas Lincoln Casey, March 6, 1896

M. J. Dummell to Thomas Lincoln Casey, March 27, 1878

M. J. Durham to Thomas Lincoln Casey, August 17, 1888

M. J. Durham to Thomas Lincoln Casey, July 30, 1888

M. J. Rogers Co. to Thomas Lincoln Casey, December 31, 1890

M. K. Rogers to Thomas Lincoln Casey, August 3, 1877

M. M. Magruder to Thomas Lincoln Casey, October 21, 1887

M. M. Mason to Thomas Lincoln Casey, March 1896

M. M. Parker to R. Ross Perry, October 24, 1891, copy

M. P. N. to Emma Weir Casey, January 5, 1883

M. R. Brown to Thomas Lincoln Casey, March 17, 1869

M. Rogers to Thomas Lincoln Casey, June 5, 1878

M. S. Brewer to Thomas Lincoln Casey, June 14, 1890

M. T. Armstrong to Thomas Lincoln Casey, September 5, 1892

M. Vétillard to Thomas Lincoln Casey, September 13, 1891

Mahan To Thomas Lincoln Casey, October 27, 1890

Major Duvall to Thomas Lincoln Casey, February 16, 1887

Major General Nelson Miles to Thomas Lincoln Casey, Augst 24, 1891

Major General Oliver O. Howard to Thomas Lincoln Casey, December 4, 1891

Major George H. Elliot to Thomas Lincoln Casey, July 29, 1879

Major George H. Elliot to Thomas Lincoln Casey, November 22, 1879

Major Gregory to Thomas Lincoln Casey, January 8, 1890

Major Henry M. Adams to Thomas Lincoln Casey, July 10, 1891

Major Henry M. Adams to Thomas Lincoln Casey, July 15, 1891

Major Henry M. Adams to Thomas Lincoln Casey, July 7, 1891

Major Henry M. Adams to Thomas Lincoln Casey, July 9, 1891

Major Rittenhouse to Thomas Lincoln Casey, June 2, 1885

Map, Washington Aqueduct - Potomac River at Great Falls, February 22, 1864

Maplewood Hotel to Thomas Lincoln Casey, September 16, 1889

Maplewood hotel to Thomas Lincoln Casey, September 2, 1889

Maplewood Hotel to Thomas Lincoln Casey, September 9, 1889

Mar. 31 for Colonel, undated

Marcus A. Casey to Thomas Lincoln Casey, July 30, 1869

Marcus Baker to Thomas Lincoln Casey, March 31, 1891

Marcus Benjamin to Thomas Lincoln Casey, July 11, 1890

Marcus Benjamin to Thomas Lincoln Casey, July 14, 1890

Margaret C. Greene to Thomas Lincoln Casey, January 30, 1883

Margaret Greene to Thomas Lincoln Casey, April 29, 1891

Margaret Greene to Thomas Lincoln Casey, October 2, 1887

Margaret L. Green to Thomas Lincoln Casey, February 19, 1883

Margaret O'Neil to Thomas Lincoln Casey, July 26, 1888

Maria Brownell Bready to Thomas Lincoln Casey, February 14, 1896

Maria L. Potter to Thomas Lincoln Casey, December 7, 1885

Maria L. Potter to Thomas Lincoln Casey, February 25, 1891

Maria L. Potter to Thomas Lincoln Casey, June 11, 1885

Marshall McDonald to Thomas Lincoln Casey, January 6, 1891

Marshall to Thomas Lincoln Casey, January 5, 1891

Mary B. Gould to Thomas Lincoln Casey, October 14, 1887