This chapter assesses the Board of Trade’s role in shaping and administering the growing British Empires of the long eighteenth century and in building the domestic state in the process. It assesses the Board’s role in shaping British trade and industry, protecting domestic manufactures, especially textiles, through protective legislation and tariff policy, alongside shipping, shipbuilding, and the slave trade. The Board supported and protected the slave trade in various ways and its entwinement in furthering British commerce and industry, including by encouraging raw materials production in the colonies. It was important in its governance role administering the colonies in North America and the West Indies and adjudicating between the different interest groups, including relations with the chartered trading companies such as the East India Company and governance of the East Asian Empire. It looks at its governance structures and relations with local governors and legislative assemblies in the North American colonies and assesses its officialdom, its extent of bureaucracy and patrimonialism in its internal structures, and how that translated into a degree of autonomy for the growing powers of the legislative assemblies. It sees this relationship as one of partnership, both with the North American and West Indian colonies, and through the corporations in the East Asian Empire, contributing to building the imperial-corporate and slave state in the process.