This chapter focuses on the preparation of the Expedition, by addressing how the American astronomers organized it, and why they decided to travel to Chile. Preparations involved getting the funding from a wealthy banker from Sacramento (Mr. Mills), but also how they built all the sophisticated equipment they needed. By connecting different enterprises, industries and expertise, in different places of the United States, they managed to have all the pieces in Mount Hamilton. This chapter also describes first negotiations with Chileans, and the story of how their desire for going south took shape, between unexpected problems and personal expectations.