Jacob Crowninshield, brother of Benjamin Williams Crowninshield, was born in Salem, Massachusetts, in 1770. He began his professional career in the field of commercial shipping, working as ship's captain and merchant for his father's merchandising firm, George Crowninshield & Sons. 

Crowninshield left the private sector to enter public service in 1801, when he gained a seat in the Massachusetts State Senate. He ran for national office, joining the U.S. House of Representatives from Massachusetts and moving to Washington, D.C., in 1803. In 1805, President Thomas Jefferson offered Crowninshield a position as secretary of the Navy after former secretary Robert Smith requested to transfer from that post to the office of attorney general. The U.S. Senate quickly confirmed him.

Crowninshield never took office, however, citing his wife's poor health and his unwillingness to leave her alone in Massachusetts. Instead, he continued his congressional career, remaining a congressman until his death in 1808 while in office.