D.B.
Good for you! What a wonderful decision!
I'm outside of Boston, so do check in with me when the time gets closer. But if you want history, we've got it! Freedom Trail (one historical site after another, from Paul Revere's House to the "one if by land, two if by sea" church, etc.). Plimouth (yes, that's how they spell it) Plantation. Old Sturbridge Village west of Boston for the mid-1800's experience. Whale watching ships out of Cape Ann (north of Boston), Provincetown (tip of Cape Cod), or Hyannis/Barnstable (also Cape Cod). Boston Tea Party ship, USS Constituion ("Old Ironsides").
You cannot beat the Cape Cod National Seashore for ocean views. There's also the Cliff Walk and the Newport RI mansions - pick 1-2 for tours, then do the Cliff Walk between them and the water. Touro Synagogue - first and one of the tiniest synagogues in the US. Charming.
Mashpee, Wamponaug and Nipmuc Native American events and festivals - check local calendars.
Lots of whaling museums/sites in Maine, Boston, Cape Cod and southern coast. Woods Hole Oceanographic Institute in Woods Hole (near Falmouth, MA) at the beginning of Cape Cod. Great museums in Boston. Salem - whaling, fishing, witch trial history - it's an amazing and well-run town.
Revolutionary War history - Lexington/Concord MA, but also Lake Champlain areas and forts.
Walden Pond - Henry David Thoreau's retreat.
Battleship Cove, southern MA - tour a US Navy ship and a submarine. Take the ferry across to Long Island's north fork, then wind your way through fishing villages and wineries, stay on the North Shore for the Vanderbilt Museum (Centerport - a gem), then go south to the amazing Long Island beaches (Fire Island, Jones Beach), then follow the south short o the Verrazano Bridge (long suspension bridge, bypasses NYC) to NJ. Head south on the Garden State Parkway to the Jersey Shore. Asbury Park is honky-tonk amusements and ridiculously fun if you get into it, Spring Lake is charming and old school.
If you go into PA, try Gettysburg and Lancaster (PA Dutch country), and the Strasburg train museum.
New York State - Finger Lakes wine & history, lake tours by boat, Erie canal, Corning museum, and of course Niagara Falls. Howe Caverns are great. Herkimer "diamond mines" are fun (18-facet quartz - very cool to take a sledgehammer to rock and find some).
When you refine this some more, come back for more details!