Q. When referring to Orville and Wilbur Wright as a unit, should the word “brothers” be capitalized—Wright brothers vs. Wright Brothers?
A. According to CMOS 8.36, “Kinship names are lowercased unless they immediately precede a personal name or are used alone, in place of a personal name.” One of the examples at 8.36 is “the Brontë sisters,” who, though none of them lived to see the age of modern aviation, provide a perfect analogy in terms of capitalization: write “the Wright brothers.”