John C. Calhoun offered a counter proposal to the Wilmot Proviso.

I'm going to need more details if I didn't answer you're question but if this is a true or false question, the answer would be true and here is more details on that sentence. The Wilmot Proviso allowed California to enter as a free state. John C. Calhoun offered a counter proposal to the Wilmot Proviso. Both Zachary Taylor and Lewis Cass ignored the issue of slavery during the 1848 presidential election.