Sometimes when doing research people need "primary sources." Most people are familiar with finding "secondary sources," like journal articles, or a book about something, but primary sources are less familar. Basically primary sources are information pieces from the time, for example primary sources on the colonial era Belgian Congo would be newspapers from the turn of the last century, or a book written by someone who was there at the time. It can be tricky to find these things, but luckily not as tricky as you might think!
One good place for those newspaper articles would be the NY Times Historical site, which has the full text of that paper, 1851-2004. Another possibility, this one in microfilm on the ground floor, is the British paper The Times of London, which we have for 1785-1998. There's lots more help available on this searching for primary documents in our Primary Sources research guide, or ask one of us for help.