In this lesson, students analyze primary source documents in an effort to answer the central historical question: Was the U.S. planning to go war with North Vietnam before the Gulf of Tonkin Resolution? The teacher begins by showing a map of Vietnam (PowerPoint) and giving students extensive background information—and a timeline—about U.S. involvement in the conflict. Students then review 4 documents: 1) the text of the Gulf of Tonkin Resolution, 2) a memo from McGeorge Bundy to LBJ, 3) a telegram from State Secretary Rusk to the Vietnamese embassy, and 4) the transcript of a phone conversation between Bundy and LBJ. Students answer extensive guiding questions for all documents and write a paragraph-length response to the central question, corroborating all that they have learned. A final class discussion evaluates the evidence.