How did a young man’s visit to a remote Caribbean island alter the course of American history? George Washington left the mainland only once in his lifetime when he sailed to Barbados in 1751. He accompanied his half-brother Lawrence, who had contracted tuberculosis, and hoped the island’s warm climate would ameliorate the disease. The four-month voyage proved to be significant for the then-19-year-old Washington. He spent time with British soldiers and viewed their fortifications and arms, which fascinated him enough to shift his career goals from being a surveyor to a military career path. Washington also contracted smallpox while in Barbados. After recovery, he gained lifelong immunity and an understanding of the benefits of inoculation. Although there were anti-immunization protests, General Washington ordered that the troops be inoculated in 1777. This decision was a significant factor in the outcome of the American Revolution. Despite its important consequences, the journey remains one of the lesser-known episodes of Washington’s early life. Historian Ralph Nurnberger details this remarkable trip and highlights its impact on Washington, his career, the outcome of the American Revolution, and medical history.