From the 1970s...
From the article:
"their RD-180 engine powers the first stage of the Atlas V, an American rocket."
Video: Atlas V Rocket Highlights"The Atlas 3 and 5 use the Russian RD 180 engine in it's first stage. A type of engine the U.S tried to build for many decades but failed to do so and gave up on it. After a visit to Russian rocket engine factory in the mid 90's they found out that the Russians used these type of engines already in the 60's!!"
"After this visit the U.S bought 101 RD 180 rocket engines. The Russian builder NPO Energomash and Pratt & Wittney are in a joint venture building derivatives from this RD 180 engine."