As texas was defending its claim to be a new and independent republic in 1836 a final crucial victory was won at

abraham lincoln was the president of usa and he had asked the audience to make a pledge on equality.

his pledge was:

“it is my earnest desire to know the will of the providence.”

lincoln also had hatred for people who condoned and practiced slavery and so he pledged:

""and if i can learnt what it is i can do it"" this is another pledge by abraham to reassure the congregation on how to deal with the providence will.

explanation:

hope this !

the answer to your question is a. the salt plains

in 1811, he led an expedition, known as the george c. sibley expedition, to improve relations with the pawnee and kansa tribes, and also to locate the rumored jefferson's salt mountain