A BSTRACT : After its independence, Mexico was visited by numerous foreigners who wrote works that spread news of its abundance in Europe. French travellers played a prominent role in this since their books helped prepare the invasion initiated in 1862. One of their interests was the legend of the wealth of Sonora, which they wanted for their country. This legend had begun in 1736 with the discovery of the Planchas de Plata mines, spread by Alexander von Humboldt at the end of the colonial era. For their part, French travellers spoke of Sonora as a true El Dorado , that Mexicans did not know how to take advantage of. In their opinion, the veins of gold, silver, and other metals that lay there had only awaited them to exploit and to reward them with endless riches.