According to the data available, the number of slaves introduced into the island from the beginning of its colonization until the year 1789 was probably not below 100,000. It is estimated that in the two hundred years between 1550 and 1750 the annual importations of the assientists into Spanish America averaged at least three thousand a year. In the census taken by Governor la Torre about 1772 Cuba was found to have 45,633 slaves. In 1775 their number had risen to forty-six thousand and that of free colored people to about thirty thousand. The relaxation of the commercial restrictions gave a strong impulse to all sorts of enterprises, mercantile and otherwise, and especially to building, and the laboring forces employed on all the new constructions were mostly slaves. By the year 1775 their proportion to the free colored population was four and sixth tenths to three. As the value of slave labor began to be recognized in that period of internal improvements and general progress, the number of slave importations steadily increased. According to Blanchet, Cuba acquired in the years 1783 and 1784 one thousand and five hundred negroes through contracts between the government and various French and Spanish firms, as also the British house of Baker and Dawson and the private shipowners D. Vicente Espon and Col. D. Gonzalo O'Farrel. Armas y Cespedes gives the number of slaves for the year 1774 as 44,333; for the year 1792 as 84,590. In the enormous number of negroes imported between 1791 and 1816 there were counted 132,000 imported legitimately, 168,000 by contraband means. A more systematized and conclusive estimate of the number of negroes gradually introduced in Cuba was made by D. Francisco de Arango, the high-minded patriot of the period of Governor Las Casas. It covers the time from the beginning of the sixteenth to the middle of the eighteenth century. D. José Antonio Saco, author of "Collecion de papeles cientifices, historicos, politicos y de etros ramos sobre la isle de Cuba, ya publicados ya ineditos," and "Historia de la Esclavitud," did the same for the eastern part of the island from 1764 to 1789. These estimates furnish the following figures: Imported on the whole island from 1523 to 1763 60,000 By the Compania de la Habana in 1764, 1765, 1766 4,957 By the Marquis de Casa Enrile from 1773 to 1779 14,132 By the permiso of 1780 authorizing the supply of negroes from French colonies during the war ending 1783 6,593 By the house of Baker & Dawson from 1786 to 1789 8,318 From the eastern part of the island, 1764 to 1789 6,000 ------- Total 100,000