I received an invitation from the Governor of New York to attend their 4th of July festivities.  Unfortunately, I am too busy here to attend. I wrote him,

Washington D. C. June 27th 1865

His Excellency, R. E. Fenton,

Governor of New York,

Sir:
As much pleasure as it would afford me to be with the good people of Albany on the 4th of July I fear it will not be possible. The experience of the last few weeks shows me that whilst we are disbanding our Armies and there is so much to do at my “Head Quarters” I should not separate myself from it until the work is done.
I am very desirous of getting a couple of months rest this Summer, as soon as the work is done so that I can absent myself so long, and must stick close at present to accomplish this. In addition to this my Chief of Staff is now absent and will remain so until the latter end of July. When he is here I can be absent for a few days without material detriment to the service.
Hoping that your celebration will prove all that is desired, I remain,
Very Truly
your obt. svt
U. S. Grant
Lt. Gn.

The Papers of Ulysses S Grant, Vol 15, p 226