an African interior began to wane with the expansion of direct colonial rule. Access to its port became increasingly awkward in the age of the steamship; and the completion of the Dakar-Saint Louis railroad in 1885 meant that up-country trade effectively circumvented its port. Large French firms, many from the city of Bordeaux, took over the new commercial networks of the interior, marginalizing the Métis traders who had always been the middle men of upstream commerce. Faidherbe also placed under direct French control large-scale seasonal groundnut cultivation near the fort systems, and then along the rail lines. This created the navétanes system of seasonal labor migration, first in Cayor, then spreading along the rail lines to Baol and Sine-Saloum, and eventually along the Thies-Kayes railway. This would be a pattern spread throughout French West Africa and French Equatorial Africa well into the 20th century. Legacy in French colonialism When he resigned his post, French rule had been firmly established over a very considerable and fertile area and the foundation laid upon which his successors built up the position occupied after 1904 by France in West Africa. The first half-century of French colonialism in Senegal produced neither solid political control nor economic gains. However, it established the basic principles for the later French advance. Senegal became the principal French base, not Guinea. French expansion was aimed towards the interior (which also encouraged expansion south in Algeria), and Faidherbe's vision of empire was confirmed. In 1863 he became general of brigade. From 1867 to early 1870, he commanded the subdivision of Bona in Algeria, and was commanding the Constantine division at the commencement of the Franco-Prussian War. Marriage and family Soon after his arrival in Saint-Louis Faidherbe took as a mistress, Diocounda Sidibe (Dionkhounda Siadibi), a fifteen-year-old Sarakolé girl. She helped him in his study of the Wolof, Pular, and Sarakolé languages. On 15 February 1857, she bore him a son, Louis Léon Faidherbe. In 1858, when Faidherbe was 40, he married his 18-year-old niece, Angèle-Emilie Marie Sophie Faidherbe. She was the daughter of his older brother, Romain, who had died eight years earlier. The marriage produced three children: Gaston, Mathilde and Wilhem. Angèle also helped care for Louis, the son of Sidibe. Another of Faidherbe's nieces, his wife's older sister Clarence, married the naval officer Théophile Aube in May 1861. At the time Aube was serving in Senegal. He would later