D. Czechoslovakia is correct. All others had been concered by Hitler and Nazi Germany.
Beginning in 1950, US involvement increased from just assisting French collision forces to providing direct military assistance to the associated states (Annam, Tonkin, Laos, and Cambodia). In May 1961 Kennedy sent 500 more military advisers, bringing American forces there to 1,400.
In the year 1882, the U.S senate passed the Chinese Exclusion act and was signed by President Chester A. Arthur. During the time period, there was many immigrants, especially Chinese, that immigrated to the United States, which caused a lot of labor. Congress decided to pass this law because a lot of Chinese people were illegally immigrating to the United States and taking away the jobs that the American Citizens wanted. The Act caused the Chinese to be ineligible for naturalization, meaning that they can't become a citizen. Because of the act, the Chinese population in the U.S during that time declined tremendously.
The Wilmot Proviso, one of the major events leading to the American Civil War, it would have banned slavery in any territory to be acquired from Mexico in the Mexican War or in the future, including the area later known as the Mexican Cession, but which some proponents construed to also include the disputed lands in south Texas and New Mexico east of the Rio Grande.
<span>This was controversial between the Southern and Northern states, because this allowed the Union to always have more representatives in the House of Representatives and would make sure that the Union could control the Southern states and vote against anything will slavery. </span>
