This is a primary source because it was directly from the event. Elvis Presley wrote this letter requesting to meet the president.

This is a secondary source because Chapin did not personally witness the event. He helped set up the meeting and wrote an article about it afterwards.

This is a primary source because it's a newspaper and many people who were there with Elvis were interviewed. Elvis's longtime aid was interviewed and a section from Prescilla's(Elvis's wife)memorial was put in the newspaper explaining why Elvis went to Nixon.

Secondary because it was made in recent times with no one who was actually at this event

This is a secondary source because it is an interpretation and depiction of the real event that happened, additionally, it does not even represent it accurately and nor does it have any of the people really involved in the real event in it.

This is a secondary source because this biography is based on multiple primary sources. Elvis's biography is a collection of first-hand accounts for his life.

Monuments are considered primary sources because they are "creative works" and also this one has the suit that Elvis wore the day of.