The # 1 song of 1970 was Simon & Garfunkel's 'Bridge over troubled water. It also became one of biggest songs of the 1970's.
And it sat on top of charts 40 years ago!
According to songfacts:
"This was one of the few songs to top the US and UK charts at the same time.Here is the song:
It was #1 in the US for 6 weeks, #1 in the UK for 3. In 1971, this won 5 Grammys: Song Of The Year, Record Of The Year, Best Contemporary Song, Best Engineered Record, and Best Arrangement Accompanying Vocalists.
The album also won Album Of The Year. Bridge Over Troubled Water was the last album Simon & Garfunkel released before they split up. It is the biggest selling ever for Columbia Records."
— Silvio Canto, Jr. (@SCantojr) June 16, 2017