Today, there is much talk about the "American pivot" back to Southeast Asia, and the role that America continues to play in terms of the geo-strategic relations between the countries in the region. That America has been a player in Southeast Asian affairs is well-known, as America's presence in countries like Indonesia, Thailand, the Philippines and Vietnam has been well documented since the Cold War. However, there has been less scholarship devoted to America's role in Southeast Asia prior to the 20th century, lending the impression that the United States is a latecomer as far as Southeast Asian affairs is concerned. This paper looks at a particular incident – the First Sumatran expedition of 1832 – where America played a visible role in the policing of the waters off Sumatra. Though the event has been largely forgotten today, and is not even mentioned in Indonesian history books, it was important for it marked America's arrival – first as a trading nation, and later as a policing power – to the region. Drawing upon contemporary sources, the paper looks at how and why the expedition was launched, and the response of the American public in its wake. It tells us something about American public perception then, and how Americans were then divided over the rile that American should play in Asian affairs.