Complex sentence: Contemporary usage of the term is generally confined to situations in which the term is considered relevant in a historical context, as in the 21st-century United States people of mixed white and black ancestry rarely choose to identify as "mulatto".
Split into simpler sentences: Contemporary usage of the term is generally confined to situations in which the term is considered relevant in a historical context. For instance, in the 21st century, United States people of mixed white and black ancestry rarely choose to identify as "mulatto".