US has held a AAA credit rating from all three major credit rating agencies (Fitch, Moody's, and S&P) for most of its history. However, with the latest downgrade in US credit rating, it is now on par with countries like Canada and Germany.
To put things in perspective, a AAA credit rating is like getting an A+ in school, A AA+ rating is like getting an A, whereas A CCC rating is like getting a D. Fitch Ratings downgraded US long-term debt late on Tuesday from AAA to AA+, earlier this tuesday.