All three spellings are correct.
*The Native Peoples which lived on the plains lived in teepees that had flaps which opened at the top in order to regulate the amount of smoke let out and fresh air let in.
*The door usually faced east toward the rising sun.
*There were teepee rules, one of which was that a person was not allowed to enter unless the door flap was open.
*Native Americans' beads were originally made of stone, bone, and sometimes metal.
*Wampum, a long string of beads, was used as currency.
*One or more beads were purposely put out-of-place to show that only the "Great Spirit" was perfect. (There are beads out-of-place on these as well.)
*The Hopewell Peoples or Mound Builders covered a large area from Louisiana up to Michigan.
*The mounds were used as temples or burial grounds.