What were Abraham Lincoln's strengths?

Lincoln's greatest strength was his ability to read people. Lincoln applied what he knew about human nature to become one of the best lawyers in Illinois before he ran for office. Lincoln was able to channel his folksy charm into gaining votes in the growing Western states during his presidential run in 1860. Lincoln's Cabinet was made up of his rivals in the Republican party in 1860—Salmon Chase, Edwin Stanton, and William Seward, among others. Lincoln allowed these men into his administration so that they would not become political rivals during his term. Lincoln saw that George McClellan would be an indecisive general long before the rest of Washington. Lincoln also saw promise in Ulysses S. Grant even though before the war he had a meager and questionable record. Lincoln's empathy shown during his trips to the Soldier's Home was not contrived, but it did make him appear human in the eyes of a Northern public desperate to end the Civil War.
Lincoln's other great strength was his perseverance. He lost political office when he spoke out against the Mexican War. He lost a spirited senatorial race against Stephen Douglas. He did not capitulate to the South's demand for independence even as the casualties mounted. He stood by the Emancipation Proclamation as a war measure even after the New York City draft riots. Lincoln was lampooned in newspapers as being a country bumpkin, but he still held the reins of leadership firmly even though there were others in the party like William Seward who would have loved to have been in charge of the country.