Thanks warrehouse. Coming from you that means alot.
I am giving this to my brother-in-law for Christmas. It is already in a "floating" frame (between two glass panes). I am trying to compile as much information as I can about the addressee, and would like to be able to date the envelope if possible.
It is addressed to R. F. Crowell, Esq.
On August 5, 1870 Mr. R. F. Crowell was assigned as Special Commissioner by the Office of Indian Affairs.
He was charged with the task of investigating the patents of those claiming to be Native Americans of the Red Lake and Pembima tribal groups in northern Minnesota.
The patent, as it was called, was the certification of Native American lineage. For those who were not full-blooded Native Americans, there was a particular concern that there might be attempts at misrepresentation by non-natives. This is because the patent was a guarantee to the bearer to receive a yearly annuity payment.
It was Mr. Crowell's job to ensure that only those who were legitimate Native Americans should receive the annuity payment.
Below is a piece of document I found showing how Mr. Crowell reported that certain people were not of Native descent and not eligible for a patent/annuity payment.

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Found Mr. Crowell's travel plans. This puts Crowell in St. Paul, MN during the year of 1871.
"REPORT OF THE SPECIAL COMMISSION IN THE MATTER OF CHIPPEWA
SCRIP, 1871.
ST. PAUL, MINNESOTA,
September 4, 1871.
SIR: The undersigned, appointed by the Hon. E. S. Parker, late Gom-
niissioner of Indian Affairs, by the direction of the honorable Secretary
of the Interior, a special commission to investigate the matter of scrip
issued under the treaty of the United States with the Ghippewas of Lake
Superior and the Mississippi, made at La Pointe, Wisconsin, September
30, 1854, and also to ascertain what persons are still beneficiaries under
the seventh clause of the second article of said treaty, as also who are
beneficiaries under article eight of the treaty made with the Red Lake
and Pembina bands of Chippewas, at the Old Grossing of Red Lake
River, on the 2d day of April, 1863, and article seven of the supple
mentary treaty of the 12th of April, 18G4, most respectfully report as
follows :
That soon after their appointment two of the commissioners, Henry
S. Neal and R. F. Crowell, proceeded to Fort Abercrombie, on the Red
River, and from thence down that river to Penibina, from Pembina to
St. Joseph, thirty miles up the Pembina River, thence back and to
White Earth, and across to Leech Lake, where they were joined by E.
P. Smith ; thence to Grow Wing, St. Cloud, and St. Paul. After re
maining some days in t. Paul they proceeded to Bayiield, Wisconsin,
with Major S. N. Clark, special commissioner so far as the matters under
REPORT OF THE COMMISSIONER OF INDIAN AFFAIRS. 241
investigation affect persons claiming to belong to the Chippewas of
Lake Superior."