To more fully understand the context of the letter above what would you, as a historian, need?

Primary sources are sources that were created during the historical period that you are studying. Just about anything that existed or was created during that time period can count as a primary source - a speech, census records, a newspaper, a letter, a diary entry, a song, a painting, a photograph, a film, an article of clothing, a building, a landscape, etc. Primary sources are documents, objects, and other sources that provide us with a first-hand accountof what life was like in the past.

Determining what is a primary source and what isn’t can get tricky - what do you do, for example, with a recent recording of your aunt talking about her experiences during the Civil Rights Movement? It wasn’t created at the time, but it’s still a first-hand account. Eyewitness accounts like oral history interviews and memoirs or autobiographies, even those recorded recently, are considered primary sources because the memories that eyewitnesses reveal in those sources were created in that historical time period, even if those memories were not talked about or formally recorded until much later.

It can get even trickier. The movie Gone With The Wind is not a primary source about the Civil War and Reconstruction, even though it is a movie about that time period. It wasn’t created during that time period and it is purely a work of fiction and therefore it can’t provide us with any credible information about that era. It could, however, be used as a primary source for the Great Depression since the movie and the book on which it was based were both produced during that period. A fictional film produced in 1930s can tell us nothing credible about the 1860s, but it could certainly tell us a lot about what people were interested in during the 1930s - their fantasy world, their dreams, their view of history, and their tastes in film. If you were writing a paper about American culture in the Depression, this would be an excellent primary source, but for a paper about slavery, it would be horrible!