In a letter dated July 28, 1859, he wrote, "There is another thing our friends are doing which gives me some uneasiness.... Douglas's popular sovereignty, accepted by the public mind as a just principle, nationalizes slavery, and revives the African slave-trade inevitably. Taking slaves into new Territories, and buying slaves in Africa, are identical things, identical rights or identical wrongs, and the argument which establishes one will establish the other. Try a thousand years for a sound reason why Congress shall not hinder the people of Kansas from having slaves, and when you have found it, it will be an equally good one why Congress should not hinder the people of Georgia from importing slaves from Africa."

While he was campaigning in Ohio, in 1859, occurred the John Brown episode at Harper's Ferry, which created intense excitement throughout the entire country and particularly in the South, where it was interpreted as an organized attempt of the abolitionists to arouse an insurrection among the slaves. In his speeches Lincoln did much to allay public sentiment in Illinois, for he construed the attack upon Harper's Ferry with his habitual common sense. He argued that it was not a slave insurrection, but an attempt to organize one in which the slaves refused to participate, and he compared it with many attempts related in history to assassinate kings and emperors. "An enthusiast broods over the oppression of a people until he fancies himself commissioned by heaven to liberate them. He ventures the attempt, which ends in little else than his own execution. Orsini's attempt on Louis Napoleon and John Brown's attempt at Harper's Ferry were, in their philosophy, precisely the same. The eagerness to cast blame on Old England in one case and on New England in the other does not disprove the sameness of the two things."

It was not long after the inauguration that President Lincoln was compelled to treat the slavery problem in a practical manner. To him it ceased to be a question of morals and became an actual, perplexing problem continually appearing in every direction and in various forms. The first movement of troops dislodged from the plantations of their owners a multitude of slaves, who found their way to the camps of the Union army and were employed as servants, teamsters, and often as guides. The Northern soldier took a sympathetic interest in the escaped slave, and as fast as he advanced into slave territory the greater that sympathy became. A Virginia planter looking for a fugitive slave in a Union camp was a familiar object of ridicule and derision, and he seldom found any satisfaction.

One day the representative of Colonel Mallory, a Virginia planter, came into the Union lines at Fortress Monroe and demanded three field-hands who, he asserted, were at that time in the camp. General B. F. Butler, who was in command, replied that, as Virginia claimed to be a foreign country, the fugitive-slave law could not possibly be in operation there, and declined to surrender the negroes unless the owner would take the oath of allegiance to the United States. A newspaper correspondent, in reporting this incident, took the ground that, as the Confederate commanders were using negroes as laborers upon fortifications, under international law they were clearly contraband of war. A new word was coined. From that moment, and until the struggle was over, escaped negroes were known as "contrabands," and public opinion in the North decided that they were subject to release or confiscation by military right and usage. General Butler always assumed the credit of formulating that doctrine, and insisted that the correspondent had adopted a suggestion overheard at the mess-table; but, however it originated, it had more influence upon the solution of the problem than volumes of argument might have had. When it became known among the negroes in Virginia that the Union troops would not send them back to slavery, the plantations were deserted and the Northern camps were crowded with men, women, and children of all ages, who had to be clothed and fed. General Butler relieved the embarrassment by sending the able-bodied men to work upon the fortifications, by utilizing the women as cooks and laundresses, and by permitting his officers to employ them as servants.

After a time the exodus spread to Washington, and the slaves in that city began to find their way across the Potomac into the military camps, which caused a great deal of dissatisfaction and seemed to have an unfavorable effect upon the political action of Maryland, West Virginia, Kentucky, and Missouri; so that President Lincoln was appealed to from all sides to order the execution of the fugitive-slave law in States which he was trying to keep in the Union. He believed that public sentiment was growing and would ultimately furnish a solution. He quoted the Methodist presiding elder, riding about his circuit at the time of the spring freshets, whose young companion showed great anxiety as to how they should cross Fox River, then very much swollen. The elder replied that he had made it the rule of his life never to cross Fox River until he came to it.

With the same philosophical spirit, Lincoln made the negro question "a local issue," to be treated by each commander and the police of each place as circumstances suggested, and, under his instructions, the commandant at Washington issued an order that "fugitive slaves will under no pretext whatever be permitted to reside, or be in any way harbored, in the quarters and camps of the troops serving in this department." This served to satisfy the complaints of the Maryland planters and the slave-holders of the District of Columbia until Congress passed the confiscation act, which forfeited the property rights of disloyal owners. That was the first step towards emancipation.

President Lincoln's plan to invest military commanders with practical authority to solve the negro problem according to their individual judgment soon got him into trouble, especially with his Secretary of War, for the latter, in his report to Congress, without the knowledge of the President and without consulting him, explained the policy of the government as follows:

"If it shall be found that the men who have been held by the rebels as slaves are capable of bearing arms and performing efficient military service, it is right, and may become the duty, of the government to arm and equip them, and employ their services against the rebels, under proper military regulation, discipline, and command."

The report did not reach the public; it was suppressed and modified before being printed in the newspapers; but that paragraph made Mr. Cameron's resignation necessary. As amended, the report contained a simple declaration that fugitive and abandoned slaves, being an important factor in the military situation, would not be returned to disloyal masters, but would be employed so far as possible in the services of the Union army, and withheld from the enemy until Congress should make some permanent disposition of them.

Lincoln was severely criticised by the antislavery newspapers of the North. But he did not lose his patience, and in his message to Congress declared his intention to keep the integrity of the Union prominent "as the primary object of the contest on our part, leaving all questions which are not of vital military importance to the more deliberate action of the Legislature." But while he was writing these guarded and ambiguous phrases he had already decided to propose a plan of voluntary abolition for the District of Columbia similar to that he had offered in Congress thirteen years before. It was a measure of expediency and delay. He evidently had no expectation that such a proposition would be adopted. He undoubtedly realized that it was impossible; but his political sagacity and knowledge of human nature taught him that the public, to use a homely but significant expression which was familiar to his childhood, "must have something to chaw on," and further illustrated his point by reminding a caller how easily an angry dog might be diverted by throwing him a bone.