On eBay, an interesting old New York State document is currently for sale, 
beginning at a price of $500, described as: 

"Marvelous 1 p. letter dated Cattaraugus Reservation, Erie county, New York, 
July 15 1848, to Millard Fillmore (later President of U. S.) as NY State 
Comptroller, Albany, from Cayuga chiefs Joseph Isaac (a/k/a D'yo-ya-tek) and 
Thomas Crow (Hon-ho-gah-dyok). Isaac, who apparently was literate signed his 
name, while Crow signed with his mark. The letter, which was written and 
witnessed by M. B. Pierce, reads: "The undersigned Chiefs of the Cayuga 
Nation of Indians in this State, write you, they are desirous to know why the 
delay of our annuities which are due us on the first day of June last. We are 
anxious to be authentically informed. We have not heard since it became due 
and we are fearful that it may be wrong somewhere. You will please to let us 
know as soon as you receive. You personally know the situation of our people, 
it is a great disappointment not to know the cause of it, is still more 
doubtful. Very respectfully, your friends, Joseph Isaac and Thomas Crow." It 
should be noted that Isaac and Crow were both signers of the 1838 Treaty with 
the New York Indians. The Cayugas were one of the Six Nations of the Iroquois 
League. Early letters signed by native American chiefs are exceedingly rare. 
Letter has Irving NY stampless cover postmarks."

It seems unfortunate this was not kept for the State Archives along with the 
other Comptrollers' correspondence.  EBay is turning into a very useful 
database just for research.  See the article "Scholars Scour eBay" in The 
Christian Science Monitor, January 14, 2003.