On the 15th of May, we received confirmed information that the President would visit Mexico on the specific dates. On the 1st of June the Secret Service was supplied by the Agency with the detailed survey of Mexican security forces that would be called upon to protect the President.
Friendly and allied governments were informed of the visit and their cooperation and pertinent informational support was solicited. From this date through the 2d of July daily information reports were furnished to the State Department, the Secret Service, the FBI and the military services.
That is from the 1st of June to the 2d of July, a period of 31, 32 days. On the 8th of June the Secret Service advance party was briefed in detail by a group of officers of the Agency on the Mexican government's plans for the protection of the President, including current information on the size, strength and capabilities of potential troublemakers.
Hazardous locations and times in the planned itinerary were identified, political and economic issues that might be invoked by hostile elements for demonstrations were specified.
On the 11th of June, the Secret Service advance party left for Mexico supported by additional security personnel to assist in coordinating an informational report and the followup activity required.
Especially prepared national intelligence estimates on the current security conditions in Mexico was approved by the United States Intelligence Board on the 13th of June.
On the 15th of June arrangements were completed to reenforce communications facilities. On the 24th of June a conference at the State Department was held at the request of the President for reviewing security measures, and this meeting I attended personally, and reported to the State Department on the essence of all that had gone before.
Emergency contingency plans were discussed and a consensus was reached that the President should make the visit as scheduled.
On the 27th of June, a final updated special national intelligence estimate was prepared, and this indicated no basic changes in the security assessment that Mexican government was prepared to cope with foreseeable security contingencies.
On the 28th of June, a final briefing report was prepared for the Director's use which indicated the security precautions of the Mexican government had effectively forestalled major organized incidents, and our informed estimate was that the President would receive a great welcome.