OneSearch located on a tab on the homepage will search many of the databases plus the library catalog simultaneously, but you might want to try searching some of these databases individually. Particularly with historical primary sources, you want to keep in mind terms that were used during that period. For example, in the newspaper articles of the day, World War I was often called the Great War. If you are searching in the text of newspapers, use: World War I or great war in the search box since either term is relevant. Searches are not case-sensitive.
The databases below cover a broad range of subjects, but they also include many useful sources for topics in history.