State:
Delaware

Appropriate age group(s):
Preschool and Younger
Elementary School
Middle School
High School & Beyond

Description:
Pipes and Drums. Fiddles, harps and folksongs. Highland dance, National dance, folk dance. Athletic competitions. Dogs herding sheep, ducks, geese or other livestock. Highland steers, Clydesdale horses and other animals. Sheep to Sweater spinning and weaving demonstrations. Story-telling, lacemaking and other arts. Children's games. Kilted golf tournaments. (Kilts, kilts Everywhere! ;-)
Food and vendors' wares. Tartan parades and ceremonies; clan and family associations. Sharing of History, and the good times of living in the here and now.

This is a sampling of what one Might find at a Celtic Festival/Highland Games near you. Each festival is as different as the individuals involved in making it happen. Much of the organization and talent is volunteer-based.

Other comment or suggestions:
MacLachlan's maintains a very comprehensive listing of Celtic Festivals and Highland Games, with regular updates to the site. Descriptions of events are listed by individual states, or by Region. Some celebrations last a single day, others an entire weekend. http://www.maclachlans.org/festival.html

Contact information for this day-trip site:
Individual festivals/games have their own websites and/or contacts. MacLachlan's can simply give you a very excellent start with finding Who, What, When and Where. Any specific data posted is subject to change, of course, so utilize contacts before embarking upon your Road Trip
;-)