Robert Fox First Baptist Church to Thomas Lincoln Casey, July 30, 1879

Robert G. Ingersoll to Robert T. Lincoln, May 26, 1884

Robert H. Hunt to Thomas Lincoln Casey, December 1, 1887

Robert H. Hunt to Thomas Lincoln Casey, December 16, 1887

Robert H. Sayre to Thomas Lincoln Casey, April 14, 1888

Robert Hunt to Lieut. Martin, May 21, 1891

Robert Hunt to Thomas Lincoln Casey, May 21, 1891

Robert M. Steele to Thomas Lincoln Casey, June 8, 1885

Robert N. Getty to Thomas Lincoln Casey, January 16, 1891

Robert N. Getty to Thomas Lincoln Casey, undated [March 1891]

Robert N. Scott to Thomas Lincoln Casey, October 30, 1879

Robert N. Scott to Thomas Lincoln Casey, undated [1879]

Robert Steele to Thomas Lincoln Casey, December 29, 1884

Robert Steele to Thomas Lincoln Casey, December 9, 1884

Robert Steele to Thomas Lincoln Casey, February 24, 1885

Robert Steele to Thomas Lincoln Casey, January 22, 1885

Robert T. Lincoln to [Robert] G. Ingersoll, May 27, 1884 [copy]

Robert T. Lincoln to [Robert] G. Ingersoll, May 28, 1884 [copy]

Robert W. Steele to Thomas Lincoln Casey, April 17, 1885

Robert W. Steele to Thomas Lincoln Casey, April 23, 1885

Robert W. Watson to Thomas Lincoln Casey, November 7, 1892

Robert W. Watson to Thomas Lincoln Casey, October 30, 1891

Robert W. Watson to Thomas Lincoln Casey, September 29, 1891

Robert W. Weir to Thomas Lincoln Casey, December 17, 1884

Robert W. Weir to Thomas Lincoln Casey, January 28, 1879; Anna C. Weir to Emma Weir Casey, January 28, 1879

Robert W. Weir to Thomas Lincoln Casey, June 1, 1883

Robert W. Weir to Thomas Lincoln Casey, June 9, 1883

Plans, Washington Aqueduct Distributing Reservoir, Plate XIII, March 1871

Plants and Bulbs, December 1, 1877

Poem: The Round of the Waters

Poem: The Watchers

Poem: There's a step between the dear one gone

Points of Superiority of the North Wing over the South Wing of the Building for State, War, & Navy Dept., undated

Poland To Thomas Lincoln Casey, December 8, 1890

Postmaster to Thomas Lincoln Casey, July 30, 1887

Pratt to Thomas Lincoln Casey, February 11, 1885

Pratt to Thomas Lincoln Casey, Thomas Lincoln Casey to Pratt to Thomas Lincoln Casey, February 10, 1885

Printed material: State Dept Blg North Wing, undated

Professor Baird to Thomas Lincoln Casey, April 14, 1884

Professor J. B. Wheeler to Thomas Lincoln Casey, February 3, 1879

Professor S. Newcomb to Thomas Lincoln Casey, January 17, 1879

Professor S. Newcomb to Thomas Lincoln Casey, May 2, 1878

Professor S. Newcomb to Thomas Lincoln Casey, undated [May 1878]

Professor Spencer Baird to Thomas Lincoln Casey, June 14, 1883

Professor William H. Burr to Thomas Lincoln Casey, January 15, 1896

Professor William H. Burr to Thomas Lincoln Casey, March 15, 1896

Professor William H. Burr to Thomas Lincoln Casey, March 9, 1896

Project of Expenditure or $500,000 appropriation asked for year 1885-6, February 4, 1885

Projections of loss of head by street and various pipe sizes, undated

Proposals for Stone, Sand, Cement and Iron, May 19, 1887