This movement was accelerated by the vices of our land tenure. In France and Germany, where the agricultural workers had a stronger interest and property in their land, they were less easily detached for factory purposes. But in England, where the labourer had no property in the land, reformed methods of agriculture and the operation of the Poor Law combined to incite the large proprietors and farmers to rid themselves of all superfluous population in the rural parts and accelerated the migration into the towns. Here the population bred with a rapidity hitherto unknown. The increase of population in England and Wales during the thirty years from 1770 to 1800 is placed at 1,959,590, or 27-1/10 per cent., while during the next thirty years, 1800 to 1830, it amounted to 5,024,207, or 56-3/5 per cent.[89] This large supply of cheap labour in the towns enabled the Lancashire and Yorkshire factories to grow with startling rapidity. The exhaustion left by the Napoleonic wars, the political disorder and insecurity which prevailed on the Continent, retarded until much later the effective competition of other European nations who were behind England in skill, knowledge, and the possession of markets. The American manufactures which had sprung up after the revolution had made considerable strides, but the conquest and settlement of vast new areas of land, and the immense facilities afforded for the production of raw material, retarded their rate of growth until long after the opening of this century. It was, indeed, not until about 1845 that the cotton manufacture made rapid strides in the United States. During the twenty years previous the progress had been very slight, but between 1845 and 1859 a very substantial and, making allowance for fluctuations in the cotton crops, a very steady growth took place.[90]