General Research Division, The New York Public Library. "Democracy and world dominion." New York Public Library Digital Collections. Accessed October 1, 2015. http://digitalcollections.nypl.org/items/510d47db-da83-a3d9-e040-e00a18064a99
Manuscripts and Archives Division, The New York Public Library. "Letter to Samuel Adams, Boston" New York Public Library Digital Collections. Accessed October 1, 2015. http://digitalcollections.nypl.org/items/bc2acb7e-4b58-0a50-e040-e00a18063320
Schomburg Center for Research in Black Culture, Photographs and Prints Division, The New York Public Library. "Armistice Day; Lenox Ave., 4 West 134th Street; Harlem, 1919" New York Public Library Digital Collections. Accessed October 1, 2015. http://digitalcollections.nypl.org/items/510d47de-1a12-a3d9-e040-e00a18064a99
Manuscripts and Archives Division, The New York Public Library. "Tennyson's Poems. (Newspaper clipping with marginalia.)" New York Public Library Digital Collections. Accessed October 1, 2015. http://digitalcollections.nypl.org/items/8b5d459a-5c6b-ca91-e040-e00a180640ef
The Miriam and Ira D. Wallach Division of Art, Prints and Photographs: Art & Architecture Collection, The New York Public Library. "The American monthly review of reviews for June." New York Public Library Digital Collections. Accessed October 1, 2015. http://digitalcollections.nypl.org/items/510d47e2-95ad-a3d9-e040-e00a18064a99
Declaration of war between USA and Germany, signed by Woodrow Wilson (1856-1924) 6th April 1917 (print), American School, (20th century) / Private Collection / Peter Newark American Pictures / Bridgeman Images
A Speech About The Government, 1916 (ink and w/c), Bateman, H M (1887-1970) / Private Collection / © H M Bateman Designs / Bridgeman Images
Try to find a variety of sources that answer your question. For secondary sources, always use vetted, scholarly sources and try not to rely exclusively on one source. Remember you are using sources to build your own argument and add your own analysis.
Primary sources enable a researcher to analyze evidence created during the time period without relying on the viewpoints of scholars. When searching for primary sources, seek different viewpoints about your topic. The better your sources, the better your research paper will be!