From a letter from Theodore Roosevelt to his son Kermit, Oct. 2, 1903:

There! You will think this a dreadfully preaching letter! I suppose I have a natural tendency to preach just at present because I am overwhelmed with my work. I enjoy being President, and I like to do the work and have my hand on the lever. But it is very worrying and puzzling, and I have to make up my mind to accept every kind of attack and misrepresentation. It is a great comfort to me to read the life and letters of Abraham Lincoln. I am more and more impressed every day, not only with the man’s wonderful power and sagacity, but with his literally endless patience, and at the same time unflinching resolution.