Most of the topics for the writing assignment are historical. You could look for an appropriate historical encyclopedia, then check the index to find an article. Fortunately there's an easier way. One of our databases, Gale Virtual Reference Library, lets you do one search and find articles from a collection of hundreds of specialized encyclopedias.
Image from Biblioteca General Antonio Machado
used under Creative Commons Attribution License
Databases for Recent Events
A few topics are too recent or too local to have much information in specialized encyclopedias. You could try to find these in a magazine database:
Databases for laws and legal questions
Additional resources for Oregon-related topics: