The series comes from the 'Current Population Survey (Household Survey)'
The source code is: LNU01373414
Source: US. Bureau of Labor Statistics
Release: Employment Situation
US. Bureau of Labor Statistics, Civilian Labor Force Participation Rate - Men, Native born [LNU01373414], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/LNU01373414/, June 2, 2015.