When was the Wilmot Proviso first brought up in Congress?

The Wilmot Proviso was first introduced in Congress in August 1846, a few months after the Mexican-American War began in May. It proposed banning slavery in territory acquired from Mexico. This was before U.S. forces captured Mexico City and before the Treaty of Guadalupe Hidalgo was signed in 1848, so the correct choice is “Just after the war started.”

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