After his brother Charles returned from London in 1769, where he had studied with Benjamin West, Peale served as his assistant and learned how to paint.

[1] Peale worked in his brother's studio until January 14, 1776, when he accepted a commission in the Continental Army as an ensign in William Smallwood's regiment.

Within three months he was promoted to captain, and during the next three years fought in the battles of Long Island, White Plains, Trenton, Princeton, Brandywine, Germantown, and Monmouth.

(One notable later collaboration, however, was in 1788 to make floats for Philadelphia's Federal Procession in honor of the newly drafted United States Constitution).

Around 1810, as Peale's eyesight began to weaken, he gave up painting miniatures to turn to large portraits and still-life subjects that were greatly admired and widely exhibited in Philadelphia, Boston, and Baltimore.