The answer would be a brought an end to the reconstruction
Guns germs and money they had better weapons, diseases that native Americans had never been in contact with and they were able to bribe some of them into helping them and giving up land
John Glenn was the first to orbit the earth
the answer to your question is a) they had advanced planning and developed effective military methods.
C) he explored parts of Canada for England who is rulers use his trip to claim much of North America