A show today about the Chesapeake. First, a book, called--“A Biography of a Map in Motion.” It’s the backstory of a map by 17th-century trader, diplomat, and immigrant Augustine Herrman. Towson history professor Christian Koot says Herrman’s map was a godsend for merchants who traveled from Delaware to Virginia, and for Lord Baltimore, who wanted to show off the growth of his colony.Then, fast-forward four centuries: Karl Blankenship, editor of the Bay Journal, on why the record growth of underwater grasses is a good sign for the Bay’s health. Read more from Karl here.