Slavery was already locked out of the territories. It was also very impractical in the territories anyways.
But keeping slavery out of the territories would have more practical and material consequences. It would drive down the demand for slaves, the price of slaves, their resale value and the wealth of slaveowners
No it wouldn't, because there was no practical use for slaves in the territories. I've covered this point many times. Rather than go to the trouble again, i'll just tell you to look at a modern Cotton growing map, and then take away the areas that require modern irrigation to work.
There was no guarantee that such an amendment would be ratified either. In the North, the amendment would have caused great controversy and a split in the Republican Party.
I've covered this too. Five Northern states did ratify it, and Seward promised New York would do so as well. With 16 slave states, plus the five Northern states that had already ratified it, plus New York, (and face it, if New York supported it, it's little satellite states would too.) it only lacked three more states to pass.
If they thought it would have worked, that amendment would have passed.
The Confederate Constitution forbade any state from abolishing slavery. If you were a slave owner, which approach would be more likely to make you feel that your claim to your human property was unassailable?
Am more interested in knowing what percentage of the voting population these people represented. I perceive it to be a very tiny percentage.
Slavery has been used in mining for centuries. There are many mines in the West. But it wasn't a question of slavery becoming as established in New Mexico as it was in South Carolina. Rather it was a question of there being enough slaves, and slaveowners, and supporters of slavery in new states to have them vote in support of the institution.
Moreover, there is cotton growing in Arizona. It was just a question of getting enough water. The Indians were growing cotton there for thousands of years and it was the major crop by the time of statehood. I don't know when "modern irrigation started, but if it was difficult to water the crop, that means more work for more slaves.
And it wouldn't have been hard to find slave buyers who thought they could make a success at slavery in the West. There were other uses for slaves: household servants, railroad builders, construction, irrigation. Oklahoma Indians had slaves and the climate there can't be so very different from that in Kansas. Do you really think that if California had split in two, as some hoped, that Southern California wouldn't be able to find uses for slaves? Most of all, the idea that if slavery couldn't expand it would die was widely believed, and limitations on slavery were perceived as an unbearable slap at Southern pride and honor.
Five Northern states did ratify it, and Seward promised New York would do so as well. With 16 slave states, plus the five Northern states that had already ratified it, plus New York, (and face it, if New York supported it, it's little satellite states would too.) it only lacked three more states to pass.
First of all, your math is wrong. Five states ratified the amendment, but two of them were slave states. Seven slave states were in rebellion and weren't going to ratify anything. They had already made their decision and weren't going to turn around. Secessionists in the other states weren't going to support any compromise measures. Seward couldn't guarantee squat, and the Upper North wasn't going to ratify the measure. So it wasn't going to be adopted.
Am more interested in knowing what percentage of the voting population these people represented. I perceive it to be a very tiny percentage.
South Carolina wasn't really a democracy back then, but if you combine slaveowers, people who wanted to become slaveowners and people who were scared of free Blacks and slave uprisings, that was probably a majority of voters in some states.
My point is that slavery was not threatened, and the Union would continue practicing legal slavery for decades more if the South had remained.
Why on earth would your opinion possibly be more important than the opinions of thousands of people who were alive at that time?