What did the loyalty order by Truman require?

The loyalty order issued by President Truman, known as Executive Order 9835, mandated a thorough background investigation of federal employees to ensure their loyalty to the United States. This order was aimed at addressing fears of communist infiltration following World War II and during the early Cold War period. The investigations were intended to determine if any employees had ties to organizations deemed subversive or disloyal. This was part of a broader effort by the federal government to safeguard national security and maintain public confidence in government workers amid growing Cold War tensions.

The other options do not accurately reflect the specific requirements of the loyalty order. For instance, while there were discussions about loyalty oaths in other contexts, the order itself did not require mandatory oaths for all citizens. Similarly, public hearings for government officials and transparency in government contracts do not align with the primary focus of the loyalty investigations mandated by Truman's order. Rather, the emphasis was mainly on assessing and ensuring the loyalty of those already in federal positions.