What are Primary Sources?
A primary source is a document or even a physical object, such as a Native American basket, which was written or created during a particular time period. These first-hand sources can provide insight into that time period or event, sometimes by bringing a sense of immediacy. Primary sources are:
Documents or objects created by its originator
From the viewpoint of a participant or observer
Not in interpreted or translated form
Examples:
The World War I Reader by 
World War I : primary documents on events from 1914 to 1919 by 
Daily Life Through American History in Primary Documents by 
The Compensation of War: the diary of an ambulance driver during the Great War by Letters Home from the Lafayette Flying Corps by The Private War of Seamson Stumpt: the unique diaries of a young German in the Great War by Testament of Youth: an autobiographical study of the years 1900-1925 by With the Armies of the Tsar: A nurse at the Russian front by The Making of a Mind : Letters from a Soldier-Priest, 1914-1919 by 
The library has the New York Times from 1851 on microfilm. You can capture the mood of the past through New York Times articles covering the Civil War and the assassination of Abraham Lincoln. The library has the New York Times microfilm from 9/1851-12/1865, 1/1913-12/2003. You can retrieve some of the articles through the online NYT archives, but you will have to subscribe for full access at New York Times Archives. However, by using the online archives to search for subjects, you locate the dates and pages of interesting articles that you can then find on microfilm. Ask a librarian at the Reference desk on the first floor for assistance with the microfilms.
The library also has the Los Angeles Times on microfilm from 1/1970-12/2003. The Los Angeles Times Archives is available online with a free 7 day trial, but afterwards, you need to subscribe.