Presumption should never make us neglect that which appears easy to us, nor despair make us lose courage at the sight of difficulties.
This appeared in Banneker's Almanac in 1794, and is commonly attributed to him, but originates earlier in "Reflections on different Subjects of Morality, by Stanislaw Leszczynski, King of Poland, Duke of Lorrain and Bar" in The Universal Magazine (1765), p. 119
Evil communication corrupts good manners. I hope to live to hear that good communication corrects bad manners.Benjamin Banneker
How pitiable is it to reflect, that although you were so fully convinced of the benevolence of the Father of Mankind, and of his equal and impartial distribution of these rights and privileges, which he hath conferred upon them, that you should at the same time counteract his mercies, in detaining by fraud and violence so numerous a part of my brethren, under groaning captivity and cruel oppression, that you should at the same time be found guilty of that most criminal act, which you professedly detested in others, with respect to yourselvesBenjamin Banneker