On September 23, 1864, Lincoln sent a letter to Blair in which he asked Blair to resign from the position of Postmaster General. While the President stated that he always appreciated Blair’s friendship and his hard work, citing, “…in the three years and a half during which you have administered the General Post Office, I remember no single complaint against you in connection therewith.”(1) Though the President gave no specific reason for his request other than stating that, “The time has come,”(2) Blair speculated in a letter to his wife, Mary Elizabeth Woodley Blair, “I suppose, however, that he thinks it will help to appease the Frémonters’(3) and Radicals, if I am dropped.”(4) Indeed this was Lincoln’s primary purpose for asking Blair to resign, despite all he had done for the Post Office Department during his three and a half years in office.
The radical Republicans had given the President an ultimatum—they would not support him in his bid for reelection unless he removed Montgomery Blair from his cabinet; if Blair was not removed, they would vote for their third-party radical Republican nominee, John Frémont. Blair, aware of the radical faction’s hatred for him, had tried to resign twice in 1864, but Lincoln refused both times. In early September 1864, the president was warned by Senator Henry Wilson of Massachusetts that “Tens of thousands of men will be lost to you or will give a reluctant vote on account of the Blairs.”(5) It was only after Lincoln discovered that John Frémont would withdraw from the presidential race if Blair was taken out of office that the President acted; as much as Lincoln liked and trusted his postmaster general, he would not sacrifice his own chances of reelection on Blair’s account. Frémont did, indeed, withdraw from the race on September 22 and Lincoln’s letter to Blair, asking for his resignation, was sent on September 23.(6) Montgomery Blair immediately resigned from his position. William Dennison, a lawyer and businessman from Cincinnati and the former governor of Ohio, was chosen by Lincoln to replace Blair as postmaster general.(7)
While radicals Republicans were appeased with Blair’s resignation, others were upset to hear the news. Gideon Welles, was extremely disappointed by Blair’s removal. The Navy Secretary called Blair’s resignation “…the greatest misfortune that had befallen the Cabinet.”(8) People from around the country expressed their unhappiness at Blair’s removal from office, with some people directing their anger towards the President:
...I intended to vote for Mr. Lincoln but I cannot support him any longer—under no circumstances whatever will I support a man who will remove a public office for being honest and capable…Hundreds look upon this move of the President's as a miserable policy and in the end will ruin him forever.(9)
Regardless of his shortcomings in temperament, Montgomery Blair was widely respected for his efficiency and work ethic as postmaster general. To many people, it seemed that Lincoln’s actions were unnecessary—losing Blair was a large price to pay in return for radical Republican support in an election that some believed Lincoln would have won without the radical vote.(10)