I'm not American and have zero clue about counties in individual states. But I always manage to scrape a point on these quizzes by guessing: founding fathers / key people in US history; colours; common surnames; geographical features; cities/towns/counties in England.
Washington, yes. Lincoln, maybe. It's always worth a try, but in the east, most counties were already named before Lincoln became famous. And he wasn't necessarily a hero in the south. I was a little surprised to find it here. Jefferson and Jackson are more reliable guesses than Lincoln.