Utah Digital Newspapers
Utah Digital Newspapers is an online repository for that state's earliest papers. The earliest—The Deseret News—dates from 1850, but most were published in the late 19th and early 20th centuries. If there's any fault with the website, it's that there's no way to perform a global search of all newspapers within a given date range, and reordering results by date doesn't seem to work. But the search function for individual papers is excellent—even allowing a "Genealogical Search" for births, marriages, or deaths, though not by date. All issues can, however, be browsed by date.