In his correspondence, Miller comments on a broad range of political and judicial issues, including Abraham Lincoln's election in 1860, Reconstruction and relations between North and South, various judicial appointments, the nomination of John Marshall Harlan to the Supreme Court, Republican Party politics, and Miller's service on the electoral commission appointed by Congress to decide the disputed 1876 presidential election between Rutherford B. Hayes and Samuel J. Tilden.

Miller, who served on the Supreme Court from 1862 until his death in 1890, relates news of the court and the status of various cases pending before it. In a confidential letter to Ballinger in 1866, he reports the Court's five to four ruling in the test oath cases striking down loyalty oaths after the Civil War. Miller briefly describes the reasoning in his dissenting opinion in the cases, yet quickly adds, in deference to Ballinger's circumstance as a former Confederate official, that he is "... not sorry that the result is adverse to my opinion, on your account and generally because I think the requirement unnecessarily harsh at present."

Correspondence of Davis addressed to his brother-in-law, Julius Rockwell, relating to political and social issues of the period. Davis discusses subjects such as Abraham Lincoln, African American social and political rights, the Civil War, Andrew Johnson and the impeachment proceedings, Reconstruction, and slavery. Other subjects include elections, national politics, issues before Congress, matters under consideration by the U.S. Supreme Court, and family affairs including travels in the South.

On microfilm. Originals held by Chicago Historical Society.