In 1854, Northern Democrats, Free-Soilers, and Conscience Whigs

a. nominated Abraham Lincoln for president.

b. united to form the Republican Party.

c. passed the Missouri Compromise.

d. sponsored the Kansas-Nebraska Act.

b.) united to form the Republican party.

The correct answer is B. In 1854, Northern Democrats, Free-Soilers, and Conscience Whigs united to form the Republican Party.

Explanation:

The United States Republican Party was founded by abolitionists, modernists, Northern Democrats, former Whigs, and former Free Soilers in 1854.

It was organized in Ripon, Wisconsin on February 28, 1854, as a party opposed to the expansion of slavery in the new territories incorporated in the Kansas-Nebraska Act. The first convention of the Republican Party was on July 6, 1854 in Jackson, Michigan. Many of his early policies were inspired by the defunct Whig Party.