Context: John Brown's raid on Harper's Ferry, which the old man hoped would start a general uprising among slaves in the South, was a failure; but it crystallized opinion on both sides of the slavery issue and brought the Civil War a step closer. Brown's raid was a source of embarrassment to the Republican Party. Some abolitionists, feeling that it came closer than any other party to representing their views, flocked to its ranks. The Democrats noted this movement and naturally tried to make the Republicans responsible for the raid. The Republicans went out of their way to deny any connection with John Brown and abolitionism. Lincoln, as leader of the Republican Party, repeated this disavowal in his Cooper Union address. This is not only the most important speech Lincoln had made up to this time but was and is considered one of his greatest. In it he set forth a course and a policy for his party, made his name known throughout the East, and paved his way to the Presidency. The address is basically a reply to the assertion by Stephen A. Douglas that the writers of the Constitution had forbidden the Federal Government to exercise any control over slavery in the territories. Lincoln as Republican spokesman departs from the middle-of-the-road policy his party has hitherto pursued and calls on it to resist strongly any aggressive move by the South to establish slavery in places where it does not yet exist. "Wrong as we think slavery is," says Lincoln, "we can afford to let it alone where it is;" but he does not feel it can be allowed to spread. Denouncing Southern talk of secession from the Union, he concludes with a ringing declaration of purpose: "Neither let us be slandered from our duty by false accusations against us, nor frightened from it by menaces of destruction to the government, nor of dungeons to ourselves. Let us have faith that right makes might, and in that faith let us to the end dare to do our duty as we understand it." It is interesting to note that in replying to the various charges which had been leveled against his party by the Democrats, Lincoln provided what many conservatives still consider the best definition of their viewpoint:
But you say you are conservative–eminently conservative–while we are revolutionary, destructive, or something of the sort. What is conservatism? Is it not adherence to the old and tried, against the new and untried? We stick to, contend for, the identical old policy on the point in controversy which was adopted by "our fathers who framed the government under which we live;" while you with one accord reject, and scout, and spit upon that old policy, and insist on substituting something new. . . .