I can fairly be called an amateur because I do what I do, in the original sense of the word - for love, because I love it. On the other hand, I think that those of us who make our living writing history can also be called true professionals.
I had been writing for about twelve years. I knew pretty well how you could find things out, but I had never been trained in an academic way how to go about the research.
My shorthand answer is that I try to write the kind of book that I would like to read. If I can make it clear and interesting and compelling to me, then I hope maybe it will be for the reader.
My next book is also set in the eighteenth century. It's about the Revolution, with the focus on the year 1776. It's about Washington and the army and the war. It's the nadir, the low point of the United States of America.