The Semidei's were among the hundreds of Corsican families which immigrated to Puerto Rico as a result of the various economic and political changes in the mid-19th century Europe; among those factors were the social-economic changes which came about in Europe as a result of the Second Industrial Revolution, political discontent and widespread crop failure due to long periods of drought, and crop diseases.

[2] Another influential factor was that Spain had lost most of its possessions in the so-called "New World" and feared the possibility of a rebellion in its last two Caribbean possessions—Puerto Rico and Cuba.

As a consequence the Spanish Crown had issued the Royal Decree of Graces (Real Cedula de Gracias) which fostered and encouraged the immigration of Catholics of non-Hispanic origin to its Caribbean Colonies.

The situation and opportunities offered, plus the fact that the geographies of the islands are similar, were ideal for the immigration of hundreds of families, such as the Semidey's, from Corsica to Puerto Rico.

The Semidei's, as did the majority of the Corsican immigrants, settled in the southwestern town of Yauco which is located in the southern coast of the island by the Caribbean Sea.

According to a New York Times article, published on August 1, 1895, the Roloff, Sánchez, Rodríguez expedition carried 280 men, 2,800 rounds of ammunition, 350 rifles 4,700 pounds of dynamite, one Gatling gun and one cannon.