Thomas MacKellar, The American Printer: A Manual of Typography
“ Lindley Murray gives the following judicious directions in regard to the use of capital letters:—It was formerly the custom to begin every noun with a capital; but as this practice was troublesome, and gave the writing or printing a crowded and confused appearance, it has been discontinued. It is, however, very proper to begin with a capital,—1. The first word of every book, chapter, letter, note, or any other piece of writing; and,2. The first word after a period; and, if the two sentences are totally independent, after a note of interrogation or exclamation. ”
