Republican President William McKinley was disturbed by the untended condition of Confederate graves near Fredericksburg in 1896 and responded favorably to the United Confederate Veterans interest in re-interring Southern veterans of the War Between the States. The Confederate Section of Arlington Cemetery was created with a monument approved in 1906 by Secretary of War and future President William Howard Taft. The 1929 US Public Law 810 authorized the Secretary of War to “erect headstones over the graves of soldiers who served in the Confederate Army”; US Public Law 85-425 of 1958 provided pensions for Confederate veterans equal to that of Union veterans.
Bernhard Thuersam, www.Circa1865.com   The Great American Political Divide
“The solemn and patriotic undertaking resulting in the attentive care now being given by the
[United States] government to the graves of the thousands of soldiers of the South who died while prisoners of war and the marking of these graves with the proper inscription of the Confederate States army was commenced by the establishment of the beautiful Confederate Section in Arlington Cemetery, the great national burial ground near Washington, and was brought about by Camp No. 1191, United Confederate Veterans, under the leadership of its commander, Dr. S.E. Lewis, now the United States Commissioner for this great work.
[Dr. Lewis has] devoted himself in all these years since 1898, when he investigated the graves of such Confederate soldiers as were buried at Arlington and in other places around the capital. Finding them in unsuitable locations, neglected, and without a soldier’s mark, in 1899 he, in conjunction with his Camp Committee on Confederate Dead, brought the matter by petition before President [William] McKinley and received his sympathy and support, which resulted in an appropriation by Congress in 1900 and in an order for reburial and proper marking by the secretary of War, April 25, 1901.
These Confederate dead, numbering one hundred and twenty-eight in the National Soldier’s Home Cemetery, in the District of Columbia, and one hundred and thirty-six in the older part of Arlington Cemetery, were re-buried . . . with new headstones and the inscriptions . . . consisting of the name and rank of the Confederate soldier, his company, regiment, State, and finally, the letters C.S.A., signifying the Confederate States Army.
The completion of the work in Arlington Cemetery opened the way [for Dr. Lewis] to extend the same attention to the graves of all Confederate soldiers and sailors, over thirty thousand, who died as prisoners of war . . .
This work of rescuing and marking soldiers’ graves under such circumstances has no parallel in history, and those whose knowledge of Confederate soldiers and sympathy with their families in our Southland led them to initiate and prosecute this great memorial have earned the lasting gratitude of every Confederate veteran and should be held in the highest esteem by all who value the honor of the South to the end of time.”
(Patriotic Work of Dr. S.E. Lewis, by E.W. Anderson, Jacksonville, Fla., Confederate Veteran, July 1914, pg. 331)