Whether you are research Upton Sinclair, Joseph Pulitzer, Margaret Bourke-White, Nellie Bly or another person fom the time period, there are several ways to locate information about your individual.
You can search for teh person, for example looking for resources written about Nellie Bly, you will use " Nellie Bly". If you want to research issues related to particular people you will identify teh issue and the person. For example, war and journalism it is best to identity a time frame. War and journalism 1899-1910.