The four river valleys:
1. Mesopotamia (Tigris- Euphrates Rivers)
2. Nile River
3. Yellow River or Huang He
4. Indus
The Louisiana Purchase occurred in direct violation of the Constitution.
The first one is the right answer
Many people visit cemeteries and memorials on Memorial Day to honor and mourn those who died while serving in the U.S. Military. Many volunteers place an American flag on graves of military personnel in national cemeteries. Memorial Day is also considered the unofficial start of summer in the United States,[4] while Labor Day, the first Monday of September, marks the unofficial start of autumn.
The holiday's exact origins are uncertain, but it came out of Civil War traditions of decorating the graves of fallen soldiers with flowers. Many cities and individuals claimed to have been the first to celebrate the event. In 1868, General John A. Logan of the Grand Army of the Republiccalled for a "Decoration Day", which was widely celebrated. By 1890 every Northern state had adopted it as a holiday. The World Wars turned it into a generalized day of remembrance, instead of just for the Civil War. In 1971, Congress standardized the holiday as "Memorial Day" and changed its observance.
Two other days celebrate those who have served or are serving in the U.S. military: Armed Forces Day (which is earlier in May), an unofficial U.S. holiday for honoring those currently serving in the armed forces, and Veterans Day (on November 11), which honors those who have served in the United States Armed Forces.[
They killed goats and sacrificed there dead babies on them