Who is John C. Fremont from The Fiery Trial: Abraham Lincoln and American Slavery and what is their importance?

John C. Fremont was a politician during Lincoln's latter career. When Lincoln first joined the new Republican party, Fremont was the chosen presidential candidate for the party. Lincoln campaigned for Fremont, attempting to encourage the Republican party to embrace a united set of values in order to draw in more support. Later, when Lincoln was President of the United States, Fremont was a general who led Union troops in Missouri. Fremont would find and execute rebels and free their slaves. Fremont also declared all slaves in Missouri free. While Lincoln quietly agreed with Fremont's policy, his need to keep the border states, specifically Kentucky, on his side, so he was forced to ask Fremont to cease and desist. When Fremont refused, Lincoln was forced to remove him from command.