"We will say to the Southern disunionists: We WON'T go out of the Union, and you SHAN'T!"
-Widely accepted end to Lincoln's Lost Speech of May 29, 1856
Reading about the Lost Speech and its probable last, or nearly last sentence reminded me of the old distinction between will and shall. We no longer observe the usage, but Abraham Lincoln certainly did.
The will/shall rule was as follows: To form the future tense, you use the modal auxilliary shall in the first person, and will in the second and third persons. Lincoln appears to be violating that rule.
There is, however, an exception: to add emphasis, the modal auxilliaries are reversed. Thus, "we won't and you shan't."
While contemporary English is simpler in this respect, it is also less precise. It reminds me that even more recent texts contain subtle distinctions that the contemporary reader would not notice.