[343] It is also suspected that he might have had a rare genetic disease such as Marfan syndrome or multiple endocrine neoplasia type 2B.[343]

Legacy
See also: Cultural depictions of Abraham Lincoln
Republican values
Lincoln's redefinition of republican values has been stressed by historians such as John Patrick Diggins, Harry V. Jaffa, Vernon Burton, Eric Foner, and Herman J. Belz.[344] Lincoln called the Declaration of Independence—which emphasized freedom and equality for all—the "sheet anchor" of republicanism beginning in the 1850s. He did this at a time when the Constitution, which "tolerated slavery", was the focus of most political discourse.[345] Diggins notes, "Lincoln presented Americans a theory of history that offers a profound contribution to the theory and destiny of republicanism itself" in the 1860 Cooper Union speech.[346] Instead of focusing on the legality of an argument, he focused on the moral basis of republicanism.[347]
His position on war was founded on a legal argument regarding the Constitution as essentially a contract among the states, and all parties must agree to pull out of the contract. Furthermore, it was a national duty to ensure the republic stands in every state.