What is the longest running number 1 single in America?

The Longest running number 1 song of ALL TIME goes to

"One Sweet Day" - Mariah Carey ft. Boys Men (#1 Debut ) and (16 weeks at #1) 1995

The Longest Running Number 1 single for 2000 - 2009 is

"We Belong Together" - Mariah Carey (14 weeks at #1) 2005

Billboard Music Awards Decade-End Charts

• Hot-100 Song of the Decade for "We Belong Together"
• Radio Song of the Decade for "We Belong Together"