Which headline does not belong?

A. “Missouri Compromise Allows Two New States into the Union”
B. “Congress Agrees to Compromise of 1850”
C. "The Northwest Ordinance Outlines Process for Statehood"
D. “Popular Sovereignty Adopted Under Kansas- Nebraska Act”

C. "The Northwest Ordinance Outlines Process for Statehood" (This headline is about a different historical event unrelated to compromises allowing states to enter the Union.)

The headline that does not belong is D. “Popular Sovereignty Adopted Under Kansas- Nebraska Act”. The other three headlines are related to compromises and laws regarding statehood and the admission of new states into the Union, while D is about popular sovereignty, which is not directly related to the process of new states joining the Union.

To determine which headline does not belong, you should analyze each headline and try to identify a unique characteristic or theme that sets it apart from the others. In this case, the common characteristic among all the headlines is that they discuss significant events or legislative acts related to the expansion and formation of the United States.

A. "Missouri Compromise Allows Two New States into the Union" This headline highlights the Missouri Compromise, which was an important legislative agreement involving the admission of two new states, Missouri and Maine, into the Union while also addressing the issue of slavery.

B. "Congress Agrees to Compromise of 1850" This headline refers to a different historical event where Congress reached a compromise to address various disputes between free and slave states, including the admission of California as a free state and the enactment of the Fugitive Slave Act.

C. "The Northwest Ordinance Outlines Process for Statehood" This headline discusses the Northwest Ordinance, which established the process for admitting new territories into the Union and outlined certain principles like religious freedom and the prohibition of slavery in those territories.

D. "Popular Sovereignty Adopted Under Kansas-Nebraska Act" This headline focuses on the Kansas-Nebraska Act, which allowed the residents of Kansas and Nebraska territories to decide whether they would allow slavery based on popular sovereignty, meaning the residents' vote would determine the status of slavery in those areas.

After analyzing the headlines, the headline that does not fit the pattern of discussing significant events regarding the expansion and formation of the United States is C. "The Northwest Ordinance Outlines Process for Statehood." While it is a historical event related to statehood, it does not specifically address the admission of two new states into the Union, as the other headlines do.