I've been to Gettysburg many many times but never during the anniversary in July. How busy is it really? Possibly compared 2 Remembrance Day
Strongly recommend Dinner reservations.
There are 2 busy areas. The battle field area and the re enactment area. Traffic is busy but I love the reenactments. Dinner reservation is good idea or take a short ride to Westminster or Frederick for some very food restaurants (reservations still good idea)
Town tends to be busier during the anniversary than it is during Remembrance Day. However, people are often spread out among the various activities going on that week. It's well worth the visit to attend these special events! This year, you can attend special programming for the anniversary of the battle July 1-3, stay in town for the 4th of July Community Concert & Fireworks, and then check out the Reenactment July 5-8. Here is an events calendar with everything going on that week - https://bit.ly/2M4JFGO. Enjoy your time spent in Gettysburg!
Just a quick update on this. I had errands to run in town today and crossed Gettysburg twice, even did lunch at Montezuma's. The traffic was not bad--in fact, it was less crowded than most weekends. I went to one of the observation towers to take some pictures of cloud formations and we even drove through the Spangler's Spring area in the evening.
Now, the reenactment doesn't start until July 5, but I thought it might be useful for people to know that July 1-3 can be totally workable.
Hope you had a great time if you decided to come!