Complex sentence: Until 1960, most Colombians emigrating to the United States were white or mestizos between this year and 1977, a period in which more than 116,000 Colombians emigrated to the United States, are becoming more ethnically diverse, representing the ethnic diversity of the population Colombian.
Split into simpler sentences: Until 1960, most Colombians emigrating to the United States were white or mestizos. However, between this year and 1977, a period in which more than 116,000 Colombians emigrated to the United States, are becoming more ethnically diverse, representing the ethnic diversity of the population Colombian.