How do you tell the difference between primary and secondary sources?

Question:

How do you tell the difference between primary and secondary sources?

Hello! I understand what both are in definition terms, but could you help be distinguish the following examples?
Thanks so much!

1) a photograph of George Washington
2) a photocopy of the front page of the New York Times dated 23 September
3) stats on the number of immmigrants who came to the US each year from 1900-1913
4) letter from PM Chretien to Pres. Bush
5) an American historian's account of the 1960 federal election written in 1999
6) tv documentary on development of Marquis wheat
7) map of Alaska Boundary Dispute taken from the Internet
8) the diary of Abigail Adams

Best Answer - Chosen by Asker: primary are numbers 1, 3, 4, 8 (the others are secondary sources)
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