Final answer:
The federal government used reasons like claims of immorality and mental instability, the belief that gay people were a security risk, and the enforcement of Executive Order 10450 to justify firing gay employees.
Step-by-step explanation:
The federal government used the following reasons for firing employees who were gay:
- Anti-homosexual crusaders argued that gay and lesbian people's innate immorality and mental instability left them vulnerable to blackmail by Communist agents. However, no evidence supported this claim.
- The government believed that gay and lesbian people were a security risk and could be easily blackmailed.
- In 1953, President Eisenhower signed Executive Order 10450, which banned gay and lesbian people from working for the federal government or its private contractors.
As a result, the FBI launched a campaign to root out gay and lesbian people from federal employment, leading to thousands of firings in the 1950s and 1960s.