Operation Lincoln was a CIA program in which travelers to the Soviet Union would be briefed before a trip to the USSR, then debriefed after they returned.
[2] From the 4,000 travelers that they screened, the CIA selected participants who spoke the native language, particularly those with technical and scientific backgrounds.
[3] As a result, in 1961, the CIA began the second phase of Operation Lincoln, which they defined as "friendly conversation to the point of revealing something useful.
"[2] Directed by Eloise Page, scientists were encouraged to gather technical intelligence during their vacations to the Soviet Union.
The CIA conducted extensive background checks on all participants to verify that they were suited for the operation and to ensure that no Soviet agents became involved.