Have each child use crayons or markers to decorate plain paper sandwich bags to look like firecrackers. Help each child gather the open end of the bag, blow air into the bag, then tie the bag closed with a ribbon. The kids can then stomp on their "popper" bags to make a loud noise, without the danger of an explosive.
Have preschoolers help pour plaster of Paris powder into bowls, then add water and stir. When the wet plaster is a desired consistency, let the kids add red food coloring to one batch of plaster. Add blue to second batch, and leave the third batch white. Help preschoolers spoon one color of the plaster mixture into a paper cup, filling cup one-third from the bottom. Then spoon in second color, and finish filling the cup with the third color of wet plaster. Let the plaster dry before tearing away the cup. Allow children to draw on paper or on an outdoor surface with their new chalk.
Have kids create a mural that looks like the night sky filled with colorful fireworks. Roll out a long piece of newsprint or use construction paper for the mural. Place the paper on an outdoor surface. Use a large brush to paint the entire paper dark blue. While the paint is still wet, have the kids use paper cups or spray bottles filled with colorful paints to make designs on the mural. The kids may splash, spray, dump or drip paints wherever they wish. Tell them to create designs they imagine a firework display in the sky would look like. After paint dries, display the mural indoors or out.
Preschoolers can create a noisy parade atmosphere by making and playing with noise-making bracelets. Cut one plastic ring from a six-pack soda bottle carrier for each child. Have the kids use paint or markers to decorate plastic margarine or other lids around three inches in size. Three to four lids are needed for each bracelet. Help kids poke a hole in each plastic lid. Thread a chenille stem (or pipe cleaner) through the hole of each lid and twist the stem around the plastic soda carrier ring. Have preschoolers wear their bracelets in a classroom parade, shaking their bracelets to accompany patriotic music.