“My confidence in Gen. Grant was not entirely due to the brilliant military successes achieved by him, but there was a moral as well as military basis for my faith in him. He had shown his single-mindedness and superiority to popular prejudice by his prompt cooperation with President Lincoln in his policy of employing colored troops, and his order commanding his soldiers to treat such troops with due respect. In this way he proved himself to be not only a wise general, but a great man, one who could adjust himself to new conditions, and adopt the lessons taught by the events of the hour”

Source: 1880s, Life and Times of Frederick Douglass (1881), pp. 433–434.
Context: My interviews with President Lincoln and his able Secretary, before narrated, greatly increased my confidence in the anti-slavery integrity of the government, although I confess I was greatly disappointed at my failure to receive the commission promised me by Secretary Stanton. I, however, faithfully believed, and loudly proclaimed my belief, that the rebellion would be suppressed, the Union preserved, the slaves emancipated, and the colored soldiers would in the end have justice done them. This confidence was immeasurably strengthened when I saw Gen. George B. McClellan relieved from the command of the army of the Potomac and Gen. U. S. Grant placed at its head, and in command of all the armies of the United States. My confidence in Gen. Grant was not entirely due to the brilliant military successes achieved by him, but there was a moral as well as military basis for my faith in him. He had shown his single-mindedness and superiority to popular prejudice by his prompt cooperation with President Lincoln in his policy of employing colored troops, and his order commanding his soldiers to treat such troops with due respect. In this way he proved himself to be not only a wise general, but a great man, one who could adjust himself to new conditions, and adopt the lessons taught by the events of the hour. This quality in General Grant was and is made all the more conspicuous and striking in contrast with his West Point education and his former political associations; for neither West Point nor the Democratic party have been good schools in which to learn justice and fair play to the negro.