This unwonted sense of power and of common interest was increased by the pressure of the British government. Just before the war broke out, plans had been set on foot in England to curb the colonies; legislation was to be more carefully revised; governors were to be instructed to hold out against their assemblies; the Navigation Acts were to be enforced. The scheme was dropped when the war began, because the aid of the colonies in troops and supplies was essential. Then arose two rival theories as to the nature of the war. The British took the ground that they were sending troops to protect the colonies from French invasion, and that all their expeditions were benefactions to the colonies. The colonists felt that they were co-operating with England in breaking down a national enemy, and that all their grants were bounties. The natural corollary of the first theory was that the colonies ought at least to support the troops thus generously sent them; and various suggestions looking to this end were made by royal governors. Thus Shirley in 1756 devised a general system of taxation, including import duties, an excise, and a poll-tax; delinquents to be brought to terms by "warrants of distress and imprisonment of persons." When, in 1762, Governor Bernard of Massachusetts promised £400 in bounties on the faith of the colony, James Otis protested that he had "involved their most darling privilege, the right of originating taxes." On the other hand, the colonies systematically broke the Navigation Acts, of which they had never denied the legality. To organize the control over the colonies more carefully, to provide a colonial revenue for general colonial purposes, to execute the Navigation Acts, and thus to confine the colonial trade to the mother-country,--these were the elements of the English colonial policy from 1763 to 1775. Before these ends were accomplished the colonies had revolted. CHAPTER III. CAUSES OF THE REVOLUTION (1763-1765.) 21. REFERENCES. BIBLIOGRAPHIES.--Justin Winsor, _Handbook of the Revolution_, 1-25, and _Narrative and Critical History_, VI. 62-112; W. E. Foster, _Monthly Reference Lists_, No. 79; Channing and Hart, _Guide_, §§ 134-136. HISTORICAL MAPS.--No. 2, this volume (Epoch Maps, No. 5); Labberton, _Historical Atlas_, lxiv.; Gardiner, _School Atlas_, No. 46; Francis Parkman, _Pontiac_, frontispiece; Putzger, _Atlas_, No. 21; B. A. Hinsdale, _Old Northwest_, I. 68 (reprinted from MacCoun, _Historical Geography_).