Here goofs

Most of the background music matches the period shown in each scene. However, in one scene set after 1776 — ostensibly marking an Independence Day anniversary — the march "Stars and Stripes Forever" by John Philip Sousa is played, even though that piece wasn't composed until 1896.

Richard's father, at one point early in the film, names several cities he claims lie along the Pennsylvania Turnpike; in reality they are all cities situated on Interstate 80 in Pennsylvania, a road that had not yet been built at the time.

The film is set in Philadelphia, yet the asteroid depicted as having wiped out the dinosaurs is shown striking that very locality. In reality, that impact occurred in the present-day Yucatán Peninsula in Mexico.