At the outbreak of the ACW, Garibaldi volunteered his services to President
Abraham Lincoln. Garibaldi was offered a Major General's commission in the U. S. Army through the letter from Secretary of State
William H. Seward to H. S. Sanford, the U. S. Minister at Brussels, July 17, 1861. On September 18, 1861, Sanford sent the following reply to Seward:
He [Garibaldi] said that the only way in which he could render service, as he ardently desired to do, to the cause of the United States, was as Commander-in-chief of its forces, that he would only go as such, and with the additional contingent power - to be governed by events - of declaring the abolition of slavery; that he would be of little use without the first, and without the second it would appear like a civil war in which the world at large could have little interest or sympathy.
According to Italian historian Petacco, "Garibaldi was ready to accept Lincoln's 1862 offer but on one condition: that the war's objective be declared as the abolition of slavery. But at that stage Lincoln was unwilling to make such a statement lest he worsen an agricultural crisis." On August 6, 1863, after the
Emancipation Proclamation had been issued, Garibaldi wrote to Lincoln:
Posterity will call you the great emancipator, a more enviable title than any crown could be, and greater than any merely mundane treasure.