Scotland made very substantial progress during the seventeenth century and the directions of future growth were becoming clearly established. There is some disagreement on the extent of Scotland's development as compared with that of England, but the achievement of a significant advance is hardly controversial. More clearly in dispute however was the wisdom of securing greater access to the English market through a full political union. Scotland's failure to improve her trading performance was underlined by the crushing failure of the colony on Darien ‘that could have been the trading hub of the world’. Yet the complete integration with England that would remove all legal barriers (imposed through the Navigation Acts) to trade with the English colonies was inhibited by the strong grass-roots nationalism deepened by English opposition to Scottish commercial initiatives. T. C. Smout explains that the main lines of Scottish economic progress were laid down in the seventeenth century through cattle, linen and tobacco but ‘almost all of them needed the Union if they were to lead to wealth’. This indicates that the events of 1707 were inevitable if Scottish commercial interests were to prosper, but were complemented by a strategic gain to England in eliminating the possibility of a foreign policy in the north that was detrimental to her interests on the continent. And both countries had a further interest in overcoming the problems of government arising from a union of crowns in the context of separate parliaments. But Scottish pride was at stake. The issues were plainly demonstrated in a flurry of legislation concerning the succession to Queen Anne in 1704–5: