From where springs the seeds of corruption...?

With the Northern administration came the wholesale corruption of the political system. In 1864, Edward Bates, Lincoln's attorney general, lamented that "the demoralizing effect of this civil war is plainly visible in every department of life. The abuse of official powers and thirst for dishonest gain are now so common that they cease to shock." 

As Henry S. Olcott, special investigator for the U.S. War and Navy Departments, revealed in The War's Carnival of Fraud (1878), "at least twenty, if not twenty-five, percent of the entire expenditures of the government during the Rebellion, were tainted with fraud." Later estimates put the level of fraud involving Army contracts at 50 percent. 

Such institutional corruption defines the post-constitutional America that Lincoln created. The destruction of the Old Republic ensured the entrenchment of a permanent kleptocracy. That is Lincoln's legacy.