It could be considered as a key to the USA'S success. Back then we needed immigrants in order to build our nation. We were once immigrants to. So without the whole idea of immigration, the U.S might not have turned out as well as it did.
Yankee - Northerner
Secede - Break away
Border State - Slave states that bordered the northern free states during the Civil War.
Union - The states that remained under the US government during the Civil War.
Confederacy - The states that seceded from the union in order to preserve slavery.
Hope this helps! If you could mark this answer as brainliest I would really appreciate it!
I'd say (B) but I'm not completely sure.
Although the United States was actively involved in World War I for only nineteen months, from April 1917 to November 1918, the mobilization of the economy was extraordinary. ... Over four millionAmericans served in the armed forces, and the U.S. economyturned out a vast supply of raw materials and munitions.