Casting HBO's John Adams Miniseries

IMDB.com indicates that Laura Linney has been cast as Abigail Adams opposite Paul Giamatti in the HBO adaptation of David McCullough’s biography of John Adams, now in preproduction.

But what about the rest of the Boston Whig crowd, not to mention the Continental Congress?

For example, for the part of John Hancock, may I suggest Tony Award-winner Jefferson Mays?