<Ul> <Li> The Wilmot Proviso banning slavery in any new territory to be acquired from Mexico, not including Texas, which had been annexed the previous year . It passed the House in August 1846 and February 1847 but not the Senate . Later, an effort failed to attach the proviso to the Treaty of Guadalupe Hidalgo . </Li> <Li> The Extension of the Missouri Compromise line was proposed by failed amendments to the Wilmot Proviso by William W. Wick and then Stephen Douglas to extend the Missouri Compromise line (36 ° 30' parallel north) west to the Pacific (south of Carmel - by - the - Sea, California) to allow the possibility of slavery in most of present - day New Mexico and Arizona, and Southern California . That line was again proposed by the Nashville Convention of June 1850 . </Li> <Li> Popular sovereignty, developed by Lewis Cass and Douglas as the position of the Democratic Party, was to let each territory decide itself whether to allow slavery . </Li> <Li> William L. Yancey's "Alabama Platform", endorsed by the Alabama and the Georgia legislatures and by Democratic state conventions in Florida and Virginia, called for no restrictions on slavery in the territories by the federal government or territorial governments before statehood, opposition to any candidates supporting either the Wilmot Proviso or popular sovereignty, and federal legislation to overrule Mexican anti-slavery laws . </Li> <Li> Two free states were proposed by Zachary Taylor, who served as President from March 1849 to July 1850 . As President, he proposed that the entire area become two free states, called California and New Mexico but much larger than the ones today . None of the area would be left as an unorganized or organized territory, which would avoid the question of slavery in the territories . </Li> <Li> Changing Texas's borders was proposed by Senator Thomas Hart Benton in December 1849 or January 1850 . Texas's western and northern boundaries would be the 102nd meridian west and the 34th parallel north . </Li> <Li> Two southern states were proposed by Senator John Bell, with the assent of Texas, in February 1850 . New Mexico would get all Texas land north of the 34th parallel north, including today's Texas Panhandle, while the area to the south, including the southeastern part of today's New Mexico, would be divided at the Colorado River of Texas into two Southern states, balancing the admission of California and New Mexico as free states . </Li> <Li> The first draft of the compromise of 1850 had Texas's northwestern boundary be a straight, diagonal line from the Rio Grande 20 miles north of El Paso to the Red River (Mississippi watershed) at the 100th meridian west, the southwestern corner of today's Oklahoma . </Li> </Ul> <Li> The Wilmot Proviso banning slavery in any new territory to be acquired from Mexico, not including Texas, which had been annexed the previous year . It passed the House in August 1846 and February 1847 but not the Senate . Later, an effort failed to attach the proviso to the Treaty of Guadalupe Hidalgo . </Li> <Li> The Extension of the Missouri Compromise line was proposed by failed amendments to the Wilmot Proviso by William W. Wick and then Stephen Douglas to extend the Missouri Compromise line (36 ° 30' parallel north) west to the Pacific (south of Carmel - by - the - Sea, California) to allow the possibility of slavery in most of present - day New Mexico and Arizona, and Southern California . That line was again proposed by the Nashville Convention of June 1850 . </Li> <Li> Popular sovereignty, developed by Lewis Cass and Douglas as the position of the Democratic Party, was to let each territory decide itself whether to allow slavery . </Li>

Who was largely responsible for getting a series of constitutional amendment proposals passed