It is not easy to know who and how they got rich from the slave trade. In Spain and Catalonia it was a rather opaque business, because the largest slave trade took place when it was already illegal. Between the 16th and 19th centuries, different European countries kidnapped more than 12.5 million people from Africa, who were shipped to the American colonies. According to current research, ships flying the Spanish flag took nearly a million people to America. The United Kingdom made the slave trade illegal in 1807, and a year later the United States (although it did not abolish slavery until 1863). Spain did not prohibit the trade until 1820; paradoxically, it became big business for Spaniards and Catalans. "More than 550,000 African captives arrived in Cuba when the trade was already illegal under Spanish law, more than half the number in all of history," says historian Martín Rodrigo, who advises the exhibition. Infamy. Catalan participation in colonial slavery, which can be seen at the Museu Maritim in Barcelona until October 5. "We have included some names in the exhibition to illustrate it, but it is a much broader phenomenon," adds the historian.