Make sure before you get too deeply committed to the topic that you can actually get the sources. Pick a topic on which you will be able to find primary sources. These are accounts of the events written by people who were actually involved in them, or witnessed them. Actual government documents are primary sources if you are studing the development of government policy. Memoirs written by people who participated in, or witnessed, the events, are primary sources.
Newspaper articles written by reporters who covered the events are usually primary sources.
History books are usually secondary sources, not primary sources. Even if they quote passages from the original documents, you are not seeing the whole documents, just the particular passages the historians choose to quote. You will almost certainly need to use secondary sources quite a bit, but don't do a paper that is all or almost all based on secondary sources. If there is only one good book on the topic you want to write about, forget it and find another topic. You want to write a paper in which you put together information from a bunch of different sources.