Abraham Lincoln succeeded for many reasons. One was he wasn't afraid of failure. In 1858, he took on Senator Douglas in the race for the United States Senate in Illinois. Few people knew who Lincoln was. Yet, that didn't stop him from running. Even though he lost that race, it gave him national prominence which helped him win the presidency in 1860.
Abraham Lincoln also understood his priorities as a leader. He was willing to do what was right for the country, even if it went his personal beliefs. He was against slavery, but he would have allowed slavery to continue where it already existed if it meant keeping the country together. Abraham Lincoln preached patience. In order to eventually abolish slavery in the South, he knew he had to wait until the timing was right. It took nearly two years after he became President for him to issue the Emancipation Proclamation. Lincoln knew issuing the Emancipation Proclamation earlier would have run the risk of losing more of the border states.
Finally, Lincoln was willing to do some unusual things. For example, to help ensure that Maryland, a border state, would stay in the Union, he detained some of the legislators in Maryland who were willing to vote for secession. After the vote was taken, he had these legislators released. This ensured that Maryland would remain in the Union. If Maryland would have seceded, Washington, DC would have been completely cut off from Union. This could not happen in Lincoln's mind. Thus, those legislators who favored secession were arrested. There are many reasons why Abraham Lincoln was successful.