
“A lie will gallop halfway round the world before the truth has time to pull its breeches on.”
Memoirs of Cordell Hull (1948), 1:220
This is a variant of similar statements attributed earlier to Mark Twain, e.g., "A lie will fly around the whole world while the truth is getting its boots on." The oldest attribution (1831) is to Fisher Ames: “falsehood proceeds from Maine to Georgia, while truth is pulling on his boots”.