"The words 'coercion' and 'invasion' are in great use about these days. Suppose we were simply to try if we can, and ascertain what, is the meaning of these words. Let us get, if we can, the exact definitions of these words - not from dictionaries, but from the men who constantly repeat them---what things they mean to express by the words. What, then, is 'coercion'? What is 'invasion'? Would the marching of an army into South California Carolina, for instance, without the consent of her people, and in hostility against them, be coercion or invasion? I very frankly say, I think it would be invasion, and it would be coercion too, if the people of that country were forced to submit." - Abraham Lincoln, February 11, 1861
It's better in context. Lincoln went on to say,"But if the Government, for instance, but simply insists on holding its own forts, or retaking those which belong to it, or the enforcement of the laws of the United States in the collection of duties upon foreign importations, or even the withdrawls of mails from those portions of the country where the mails themselves are habitually violated; would any or all of these things be coercion? Do the lovers of the Union contend that they will resist coercion or invasion of any state, understanding that any or all of these would be coercing or invading a State? If they do, then it occurs to me that the means for the preservation of the Union they so greatly love, in their own estimation, is of a thin and airy character."