Less than a decade after the American Civil War, the United States signed the 1874 reciprocity treaty, imposing its first restrictions on Hawaiian sovereignty. Whereas most scholars take for granted US interests in controlling Hawaii, we ask how this interest emerged in 1874. We argue the answer lies with American entrepreneurs like Henry A.P. Carter. The rise of commodity prices - first in sandalwood, then in whale oil, and finally, in sugar - drove American entrepreneurs to Hawaii. When threats to their enterprises emerged, they formed a lobby to advocate for American imperialism, and shaped perceptions of the costs and benefits of imperialism within Hawaii and the United States.