BRITAIN’S SELF-INTEREST as regards her empire on the American continent in the 18th century was clearly to maintain her sovereignty, and for every reason of trade, peace and profit to maintain it with the goodwill and by the voluntary desire of the colonies. Yet, through the fifteen years of deteriorating relations that led up to the shot heard round the world, successive British ministries, in the face of constant warnings by men and events, repeatedly took measures that injured the relationship.