In the mid-19th century, two former presidents ran for their old office as candidates of third political parties. Both efforts fell victim to the traditional two-party system of the United States.

In 1948 the United States had just won the Mexican War. As a result, Mexico “ceded” to the U.S. all of its land from Texas to the Pacific Ocean and up to the California-Oregon border. This area, called then the Mexican Cession, is today’s American Southwest.

Many Southerners hoped to expand slavery into this new section of the country but many Northerners were adamantly opposed to that idea. This con...