Life is a hard battle anyway. If we laugh and sing a little as we fight the good fight of freedom, it makes it all go easier.

Sojourner Truth (1797-1883) American abolitionist, women's rights activist [b. Isabella Baumfree]

Quoted in Elizabeth Cady Stanton, Letter to the Editor, New York World (13 May 1867)
    (Source)

Recorded in Stanton, Anthony, Gage, History of Woman Suffrage, Vol. 2 "1861-76", Appendix to Chapter 18 (1881).

This quote is often given with the following sentence appended to it:

I will not allow my life's light to be determined by the darkness around me.

However this is not in the original, and I have been unable to source it.