HBO and Playtone have teamed to buy rights to David McCullough’s book “1776,” and will use it as the basis for a multi-part miniseries about George Washington’s charge against the British. The mini will be exec produced by Playtone partners Tom Hanks and Gary Goetzman. The network and producers are negotiating with screenwriter Kirk Ellis to spearhead the project. Though he mined the setup and behind-the-scenes political maneuverings of the American Revolution in “John Adams,” McCullough went right back to the subject with “1776,” an excerpt of which is the current cover subject of Newsweek. The mini will be devoted to how Washington waged the war. It will explain his strategy in leading the troops and the chess game he played with the British. He was vastly outmanned, but luck, courage and character drove Washington and his troops to vanquish the Brits.