Long before the popularity of telephones and telephone books, urban communities listed their residents in city directories and rural communities often had county directories as well. For many areas, publication began in the early to mid-1800s and continued well into the twentieth century. City directories are especially helpful in tracking city dwellers, who often did not own property and may have changed residences more frequently than those who lived in the country. Like phone books, both city and county directories have multiple sections in which you can find listings of people, non-profit organizations and businesses, and many interesting paid advertisements. Best of all, directories were often issued yearly, so they can help fill in the gaps between censuses.