One type of resource very useful in the initial stages of doing research for a history paper is a bibliography. Many persons, upon hearing the word "bibliography" think only of a listing of sources at the end of a research paper, journal article, book, etc. While those are certainly examples of bibliographies, the term "bibliography" has a broader meaning. Bibliography etymologically means "writing about books". Practically that can encompass many things. One type of bibliography is a subject bibliography: a list of sources that the compiler of the bibliography (or "bibliographer") located, identified, and examined and judged were useful and relevant for research on a particular subject. Subject bibliographies come in many forms; some are compiled by historians, curators, archivists, librarians at a particular institution; other bibliographies are actually published as books themselves. An "annotated bibliography" not only lists works on a certain subject but provides the bibliographer's short evaluative statement on the work, commenting on strengths, weakness, how it might be useful, etc.
Bibliographies of all types are very important to military history, and subject bibliographies of the Civil War in general and various aspects of it (including the 2nd Bull Run Campaign) abound. They may be of great use to you in the initial stages of your research. They can help you identify additional secondary sources as well as primary sources that go beyond the ones which you have already been provided.
IMPORTANT: one of the most useful aspects of a subject bibliography is that it can help you identify works that would not be likely to appear in online searches. This is because a work might be *about* a certain subject even though keywords related to that subject do not appear in the title nor consistently enough in the text to generate a return in electronic search results. You should learn how to use both online searching of various databases *and* bibliographies in combination
Sometimes bibliographical work is combined with explanatory material on the historiography of a subject; this type of work is often called a published research guide. You might think of this kind of work as a "bibliography plus" in a sense. Here is an example of one such work:
(An e-book version is also available: Woodworth, Steven E. The American Civil War: a Handbook of Literature and Research. Westport, CT: Greenwood Press, 1996. E-Book version)
Pay careful attention to the publication date. On the one hand, because it was published almost 25 years ago, it will neither list nor explain much recent and important historiography. Does this mean it is useless? No. It can still help a research gain a basic understanding of the historiography of a subject up to the point the research guide was published.
Sometimes bibliographers compose bibliographies of a more narrowly-defined subject. For example, academic military historians often find useful bibliographies of the activities and history of a particular military unit, or a bibliography on a single particular battle or campaign. The latter may range in length from a few pages to an entire published book. Some bibliographies are published only online.
Particularly useful examples of specialized bibliographies published online include those produced by the U.S. Army Heritage and Education Center. (USAHEC). Several ones useful for studying the American Civil War overall and the 2nd Bull Run Campaign in particular are linekd below:
Many excellent examples come from a project of the New York State Military Museum, who has a unit history project which gathers information (including primary and secondary source material) on New York militia, volunteer and (later) National Guard units raised in the State of New York. The section on the Civil War is quite large and of great use to researchers studying any Civil War battle, including the 2nd Battle of Bull Run. For example, a researcher who examines the organization of the page and notices that unit listings are organized by arm of service and who then clicks "Infantry" will find a listing of a large number of New York volunteer units from the Civil War. One could refer to an order of battle to determine which units were relevant to whatever aspect of the 2nd Battle of Bull Run is of interest and then check the page for that unit. A little investigation quickly reveals that each unit page includes a very useful bibliography, such as the one for the 73rd New York Infantry. (Note that this single link is given here on this subject guide simply as an example; researchers should examine closely the New York State Military Museum unit history project pages directly as they contain a wealth of useful bibliographic information.)