Washington DC and ? recommendations

Put the Smithsonian national air and space museum on your list.

In DC: Smithsonian museums: https://www.si.edu/museums

Chincoteague and Assateague Islands. Wild ponies on the latter.

Baltimore: National Aquarium. American Visionary Art Museum.

We usually stay out at Springfield-Franconia area south of D.C. It's where the junction of I-95 and I-495 is.

The metro line ends there, and it's an easy ride into the center city to visit the Smithsonians and the Holocaust Museum.

So much to do in DC, but it’s nice to get out of the city and explore too!

There’s Mount Vernon, home of George Washington. It’s right outside DC in Northern VA. Arlington Cemetery would be another interesting stop in the same area.

There is a second Air and Space Museum (in addition to the original) also in Northern VA, if the kids are into flight.

If anyone likes presidential history there are three presidential historic homes in the Charlottesville VA vicinity:

Monticello (Thomas Jefferson)
Montpelier (James Madison)
Highland (james Monroe)

IMO, Monticello is the most extensive of the three and had the nicest tour of the three. I’ve been there as a teenager and as an adult, and it would be enjoyable for kids, I think.

What about Shenandoah National Park (depending on the season) or Harpers Ferry WV?

Our daughter still talks about the trip we took to Gettysburg when she was in Jr Hi. We stayed in an inn that had a lot of cats, including Longstreet. We took a horseback ride on the battlefield. We ate in a restaurant that had a hiding place for the Underground Railroad that they had glassed in so you could see it. Sorry I don't remember the names of these places.

I'm an aerospace enthusiast, so I would join AussieNomad in heartily recommending the National Air and Space Museum. It has 2 locations -- the National Air and Space Museum in the city and the Steven F. Udvar-Hazy Center near Dulles Airport. Both are spectacular and worth seeing. The Udvar-Hazy Center has a dizzying array of aircraft (a Concorde, the Enola Gay, many military planes) and the space shuttle Discovery. To me, the space shuttle alone is worth going to see.

As for a second location, how about Norfolk/Virginia Beach? It might be of particular interest if you are interested in military/navy sorts of things. You get beach. You get the Norfolk naval base. There is a 2-hour cruise that will take you by the naval base and let you see what ships are in port. We got to see a nuclear sub coming into port, which was pretty cool. The USS Wisconsin, one of the last battleships the US built, can be explored at the Nauticus center.

Aerospace Museum: https://airandspace.si.edu/
Nauticus website: https://nauticus.org/
Boat tour website: https://www.navalbasecruises.com/

Gettysburg is about 1.5 hrs by car from DC. The battlefield tour there is fascinating and can take most of a day if you want to do a deep dive into a significant part of American history. The town is quite pretty with many lodging options if you want to overnight there. Though it can be congested at midday when the tours are running things mellow out quickly after around 4 PM.
The Pennsylvania Dutch country nearby is worth a meandering drive, maybe with a stop in Hershey for a chocolate fix.
Skyline Drive and the Blue Ridge Parkway southwest of the city are nice, particularly in Autumn when the trees are ablaze with color.

The National aquarium in Baltimore is nice, but fairly pricey. If you decide to go towards Baltimore stop at Fort McHenry (National anthem). Popular eastern shore beaches include Ocean City, Bethany, and Dewey. Gettysburg battlefield is more like a 2-2.5 hours drive from Washington DC mostly due to traffic. Lancaster county is a popular destination with some interesting small towns, the Strasburg railroad, and the Amish with their buggies. Of course, there’s Hershey and Hershey Park. West of DC is Skyline drive in Shenandoah National Park. If you like caves there are a few near it. The most popular is Luray Caverns. If you like zoos the National Zoo is interesting and worth visiting. Many people go just to see the pandas.

Edited: if you go to Luray caverns, nearby (19 miles) is the Route 11 Potato Chip factory in Mt. Jackson. The factory is small and you can watch the chips being prepared and packaged. The visit is free and one can try every variety of chip it makes for free. The samples are packaged not just sitting in a bowl. The children would probably like it.

Gettysburg and Colonial Williamsburg. Both iconic for American history,

How about a loop something like:

-- head south of DC, stop at Mount Vernon
-- head down I95, visit Civil War battlefield sites in Fredericksburg, Spotsylvania (I remember these from my childhood as being excellent, but I haven't visited in a long time)
-- Richmond (stop and visit, plenty of things to do depending on your interests)
-- head out I64, visit colonial Williamsburg and/or Busch Gardens, again, depending on your interests
-- then for a beachy area, head up to Chincoteague/Assateague (or you could just go to Virginia Beach, which is closer)
-- loop back up through Maryland to get back to DC

I don't know if you have a car or not but Fredericksburg is about an hour or so south of DC and has a historic downtown area as well as numerous battlefield and walking/hiking paths. If it's not too cold you could always look at spending a few days at the Delmarva shore like Rehobath or Dewey Beach. I usually stay at Lewes which has a lot of historic sites as well as a beach.

Harpers Ferry WV- historical and has lots of outdoor hiking.

Wanted to mention that although the Smithsonian museums are free of charge, some require (free) timed-entry tickets - the Aerospace museum, and the Museum of African American History and Culture. It might also be a possibility for special exhibits at other museums.

I’ll add that, at least prior to Covid, active duty or retired military only needed to show their ID cards and could enter the museum without a timed-entry ticket. I used mine to get my family into the holocaust museum and some friends into the African American museum without timed entry. Just something to think about if you fall into either of those categories.

I don't believe anyone has mentioned the National Zoo in Washington, which is part of the Smithsonian. It's free, but there's a steep ($30) charge for parking. There are Metro stations both north (Cleveland Park) and south (Woodley Park - Zoo) of the zoo. It's uphill as you head north. The zoo is large, so seeing the entire thing involves a lot of walking. It might be best to consult a map ahead of time and focus on the areas of most interest. I'm not sure there are maps available at the zoo itself; there's a printable map on the website.

A ticket (not timed) is required for entry; it must be obtained online in advance. There is some food available in the zoo, but I've never eaten there. There are quite a few restaurants along Connecticut Avenue, between the two Metro stations.

Also the National Gallery of Art in DC, two buildings with many outstanding works, the Hirschhorn Museum of modern art, and the Sackler Gallery of Asian Art, The Corcoran Gallery and Phillips Collection are also renowned. And up in northwest DC, not far from the zoo, is Washington Cathedral, a Gothic building like the European cathedrals but built over most of the 20th century. Good practice for the somewhat older ones in Europe. These kinds of things may not appeal to most teenagers, but you never know. Its easier and cheaper to find out in DC than to fly them across the Atlantic.

The easiest beaches to reach from DC would be straight east on Route 50, across Chesapeake Bay to places like Rehoboth, Lewes, Bethany Beach, and Ocean City. Kind of far for a day trip from DC but I guess some people do it.

The Corcoran Gallery closed permanently in 2014. The Internet tells me its holdings were given to the National Gallery of Art.

Take them to Ocean City, Maryland or Fenwick Island, Delaware. I spent many summers there as a young teenager and loved it. Beach days, the boardwalk at Ocean City is kitchy and fun, there's putt putt golf around and go carts and you could stop in Annapolis on the way or on the way back.

Lots of great suggestions. I lived in N. Va for five years and did the city well. BEWARE of the awful traffic in the area. Getting from place to place, parking, driving in heavy traffic will slow down your abilities to visit.

Sorry, but the beaches near DC are a long way off and not so great. Also, they are very crowded. Many in that are go to North Carolina for the nice beaches.

Maybe it's changed now, but in fall of 2021, some Smithsonian museums were closed on several weekdays. We went to the Zoo on a day when none of the museums we wanted to see were open. (We had been to those museums on earlier trips, so it wasn't a huge disappointment ) I would look up the opening days for the museums you want to see before making plans during the week.