There's little doubt that Lincoln was one of the most influential and important leaders ever elected to the White House.
Getting the Republican Party's nomination in 1860 and then defeating Democrat Stephen Douglas involved some sly political moves by Lincoln's team.
He wasn't above 'dirty politics'
Lincoln's 1858 Senate race against Douglas was dirty: Douglas even encouraged votes by providing liquor to those who supported him. It was a devastating loss for Lincoln -- but when he sought the Republican presidential nomination two years later, he didn't shy away from such maneuvers in his campaign.
"Even our greatest president, our most honest president wasn't above a little dirty politics," said Paul Begala, a CNN contributor
who was senior strategist for President Bill Clinton's 1992 campaign.
Lincoln secretly purchased a German-language newspaper featuring favorable articles about him to help curry favor among its readers, mostly immigrant voters, Lincoln scholar and biographer Harold Holzer pointed out in a CNN essay
Ahead of the 1860 Republican National Convention in Chicago, Lincoln's campaign team, led by Judge David Davis
, met with delegation leaders, sometimes promising Cabinet-level positions in exchange for support for Lincoln.
"They worked their way into every nook, cranny and snook-filled hall they could," said Allen Guelzo
, author of several books on Lincoln and a professor at Gettysburg College.
Lincoln's campaign aides even printed out 5,000 counterfeit tickets to the Republican convention to pack the halls with his supporters.
"Make no mistake, Abraham Lincoln was chief political strategist: He relied on his aides maybe sometimes to do the dirty work, to be ruthless, to cut deals, but he was the lead dog," said David Plouffe, President Barack Obama's campaign manager in 2008.
He contemplated sending freed slaves back to Africa
Lincoln was firmly against slavery -- yet his position on what should happen to freed slaves wasn't so clear.
"The problem arises with the next question: What do you do with slavery, given that it's unjust?" historian and author Eric Foner told NPR
. "Lincoln took a very long time to try to figure out exactly what steps ought to be taken."
He wavered on his views of what should be done with freed slaves. Even his historic Emancipation Proclamation
, which he delivered as President in 1863, stopped short of granting citizenship or any other rights to African-Americans -- stating only that freed slaves should be paid "reasonable wages" for their work and should be allowed to serve in the U.S. military.
"Lincoln does not really see black people as an intrinsic part of American society," said Foner, who outlined Lincoln's evolving views on slavery in his book "The Fiery Trial: Abraham Lincoln and American Slavery.
"They are kind of an alien group who have been uprooted from their own society and unjustly brought across the ocean. 'Send them back to Africa,' he says (in an 1854 speech). And this was not an unusual position at this time."
As a candidate for Senate in 1858, Lincoln stated during his fourth debate
with Douglas, "I am not, nor ever have been, in favor of bringing about in any way the social and political equality of the white and black races."
But his views evolved over time. And Foner said that the Emancipation Proclamation, which freed slaves in 10 rebellious Southern states, "completely repudiates all of those previous ideas for Lincoln."
He ran for the U.S. Senate twice -- and lost both times
If you thought Lincoln was a U.S. senator before he got to the White House -- well, you're not the only one
Lincoln served in the Illinois House of Representatives for four terms before seeking higher office. After a single term in the U.S. House, he first ran for a Senate seat in 1845 -- a race he lost by five votes.
Despite his clear victory over political rival Douglas in the famed debates of 1858, he also lost that Senate race to Douglas.
Word got around about the passionate politician and his powerful anti-slavery speeches at those debates.
"Newspapers across the country that had begun reporting the debates in August in order to cover Douglas ended in November by featuring Lincoln," Guelzo wrote
. "Lincoln gained a national reputation that it would have been impossible to acquire in any other way."
Lincoln was invited to speak at a Republican event in New York's Cooper Union in February 1860 -- and delivered an impressive speech that Holzer noted
"dramatically catapulted (him) toward the White House."
With his star on the rise, Lincoln still smarted from his Senate losses. In 1859 he told a fellow Illinois congressman, "I would rather have a full term in the Senate than in the presidency."
He most likely suffered from clinical depression
Joshua Wolf Shenk, author of "Lincoln's Melancholy,
" analyzed the work of historians who reviewed the original accounts of the men and women who knew Lincoln the best.
These scholars surmised that Lincoln's widely reported "melancholy" had all the signs of the three major stages of depression: fear, engagement and transcendence.
"He often wept in public and recited maudlin poetry," Shenk wrote in The Atlantic
. "He told jokes and stories at odd times -- he needed the laughs, he said, for his survival.
"As a young man he talked more than once of suicide, and as he grew older he said he saw the world as hard and grim, full of misery, made that way by fate and the forces of God."
He was aware of an assassination plot against him
Four years before John Wilkes Booth famously shot and killed Lincoln
, the newly elected U.S. leader was fully aware his political enemies had been plotting his death.
Those entrusted with his security had tried to persuade Lincoln to reschedule a multicity train tour leading up to his March 1861 inauguration in Washington.
A detective hired by the railway "told Lincoln in blunt terms that if he kept to the published schedule, 'an assault of some kind would be made upon his person with a view to taking his life,' " Daniel Stashower wrote in Smithsonian Magazine
Lincoln even hinted at his awareness of this danger during a speech at Philadelphia's Independence Hall in February 1861
as he tried in vain to prevent a civil war:
"If this country cannot be saved without giving up that principle (of liberty, outlined by the Declaration of Independence), I was about to say I would rather be assassinated on this spot than surrender it."
Lincoln agreed to continue his journey in an unmarked train car. Aware that secessionist plotters wanted to prevent Lincoln's inauguration, army soldiers were dispatched along Pennsylvania Avenue as additional security.