Dear Ms. Hernandez,
Thank you for posting on History Hub!
It is possible that you will locate relevant information relating to in anti- communist and covert operations in Colombia within the Department of State central file, part of RG 59: General Records of the Department of State. The records consist of communications back and forth between the Department of State and American diplomatic and consular posts, internal Departmental documentation, communications with other government agencies and private organizations and the public, communications with diplomatic and consular officials from other countries in the United States, and related materials. More detail is at: http://www.archives.gov/research/foreign-policy/index.html.
Based on the file manual, we would recommend beginning with the following files in the 1950-54 portion of the Central Decimal File:
721.52 - Intelligence and Subversive activity in Colombia
711.5221 - Intelligence activities, espionage, of country ** (US) in country ## (Colombia).
721.001- Communism in Colombia
For the 1945-1949 portion of the Central Decimal Files:
821.00B Communism. Communistic activities
If you have not already done so you should consult FOREIGN RELATIONS OF THE UNITED STATES (FRUS). This is a State Department publication of selected documents from State Department files and other sources. Besides providing the text of important foreign policy documents, FRUS also provides the source file numbers (printed either with the document or as footnotes) which are the keys to obtaining access not only to the printed item but to other documents on the same subject but not selected for publication. Volumes are available online at http://www.state.gov/r/pa/ho/frus/
We hope this information aids you in your research!