William H. Seward quotes and sayings page 2 (statesman). Here's quote # 11 through 20 out of the 21 we have.
“Sir, there is no Christian nation, thus free to choose as we are, which would establish slavery.”
“But you answer, that the Constitution recognizes property in slaves. It would be sufficient, then, to reply, that this constitutional recognition must be void, because it is repugnant to the law of nature and of nations.”
“I speak on due consideration because Britain, France, and Mexico, have abolished slavery, and all other European states are preparing to abolish it as speedily as they can.”
“But there is a higher law than the Constitution, which regulates our authority over the domain, and devotes it to the same noble purposes.”
“I deem it established, then, that the Constitution does not recognize property in man, but leaves that question, as between the states, to the law of nature and of nations.”
“I mean to say that Congress can hereafter decide whether any states, slave or free, can be framed out of Texas. If they should never be framed out of Texas, they never could be admitted.”
“The United States are a political state, or organized society, whose end is government, for the security, welfare, and happiness of all who live under its protection.”
“It is the maintenance of slavery by law in a state, not parallels of latitude, that makes its a southern state; and the absence of this, that makes it a northern state.”
“Simultaneously with the establishment of the Constitution, Virginia ceded to the United States her domain, which then extended to the Mississippi, and was even claimed to extend to the Pacific Ocean.”
“The proposition of an established classification of states as slave states and free states, as insisted on by some, and into northern and southern, as maintained by others, seems to me purely imaginary, and of course the supposed equilibrium of those classes a mere conceit.”