Actually that would be laws against sodomy that were deeply rooted in our nation’s history.
http://www.pbs.org/wgbh/pages/frontline/shows/assault/context/employment.html
Employment of Homosexuals and Other Sex Perverts in Government (1950)
Interim Report submitted to the Committee on Expenditures in the Executive Departments by its Subcommittee on Investigations pursuant to S. Res. 280 (81st Congress). A Resolution Authorizing the Committee on Expenditures in the Executive Departments to Carry Out Certain Duties....
Conclusion
. . . It is the opinion of this subcommittee that those who engage in acts of homosexuality and other perverted sex activities are unsuitable for employment in the Federal Government. This conclusion is based upon the fact that persons who indulge in such degraded activity are committing not only illegal and immoral acts, but they also constitute security risks in positions of public trust.