I'm assuming you'ret talking about either WWII or WWI, but it's the same concept. They made sure everybody knew about it. Posters were everywhere letting people know about their fellow Americans in the war and to donate lots of money and supplies.
Hope this helps!!
To ensure that the Aryan race was to become the master race and to ensure that the population was increased to fight for Germany in WW2
Manifest Destiny was largely led and carried out by white americans seeking the westward expansion to increase the boundaries of the United States. African Americans were impact largely because as westward expansion continued new states were brought into the union with legalized slavery in places like Texas. This had an overall negative impact on African Americans by increasing the demand for slavery and expanding the institution of slavery westward. For the Native Americans Manifest Destiny was a major catastrophe leading to the ethnic cleansing and removal of Native Americans from their homes and lands. This removal often occurred with force with high rates of violence.
They mostly grew wheat, barley, oats, rye, and corn. because of this, they were basically known as the "Breadbasket". So I believe your answer would most likely be wheat.