[3] Considered one of the Founding Fathers of the United States,[4] Carroll was known contemporaneously as the "First Citizen" of the American colonies, a consequence of signing articles in the Maryland Gazette with that pen name.

He was part of an unsuccessful diplomatic mission, which also included Benjamin Franklin and Samuel Chase, that Congress sent to Quebec in hopes of winning the support of French Canadians.

After retiring from public service, he helped establish the Baltimore and Ohio Railroad by purchasing $40,000 of state-backed securities and serving on its first board of directors.

[6] The Carroll family were descendants of the Ó Cearbhaill's, who were the rulers of the Irish petty kingdom of Éile in King's County, Ireland.

[6] He was born an illegitimate child, as his parents were not married at the time of his birth, for technical reasons to do with the inheritance of the Carroll family estates.

[15] The young Carroll was educated at a Jesuit preparatory school known as Bohemia Manor in Cecil County on Maryland's Eastern Shore.

Like his father, Carroll was a Catholic and as a consequence was barred by Maryland statute from entering politics, practicing law and voting.

[15] This did not prevent him from becoming one of the wealthiest men in Maryland (or indeed anywhere in the Colonies),[15] owning extensive agricultural estates, most notably the large manor at Doughoregan, Hockley Forge and Mill, and providing capital to finance new enterprises on the Western Shore.

[17] Carroll was not initially interested in politics,[15] and in any event Catholics had been barred from holding office in Maryland since the 1704 act seeking "to prevent the growth of Popery in this Province".

Writing in the Maryland Gazette under the pseudonym "First Citizen," he also criticized the royal governor's proclamation that increased special fees paid by colonists to state officials and Protestant clergy.

Opposing Carroll in these written debates, using the name "Antillon", was Daniel Dulany the Younger, a noted lawyer and Loyalist politician.

[21] Dulany soon resorted to highly personal ad hominem attacks on "First Citizen", and Carroll responded, in statesmanlike fashion, with considerable restraint, arguing that when "Antillon" engaged in "virulent invective and illiberal abuse, we may fairly presume, that arguments are either wanting, or that ignorance or incapacity know not how to apply them".

In early 1776, the Congress sent him on a four-man diplomatic mission to the Province of Quebec, in order to seek assistance from French Canadians in the coming confrontation with Great Britain.

He arrived at the 2nd Continental Congress[6] too late to vote in favor of the Declaration of Independence but was present to sign the official document that survives today.

In November 1779, the Maryland House of Delegates moved to pass a bill authorizing the confiscation of property from those who would not renounce their allegiance to England, without any right to a legal hearing or remedy.

; let an effectual mode of getting rid of it be pointed out, or let the question sleep forever;"[27] However, although he supported its gradual abolition, he did not free his own slaves.

Named in his honor are counties in Arkansas, Georgia, Illinois, Indiana, Iowa, Kentucky, Maryland, Mississippi, Missouri, New Hampshire, Ohio, and Virginia as well as two Louisiana parishes, East and West Carroll.

Cities and towns named for him are in Georgia, Kentucky, Iowa, Maryland, Missouri, and New York, as well as neighborhoods in Brooklyn and Tampa.

[41] Paca-Carroll House at St. John's College is named for Carroll and his fellow signer of the Declaration of Independence, William Paca.

[46] In the 1940s, newspaper journalist John Hix's syndicated comic Strange as It Seems published an apocryphal explanation for Charles Carroll's distinctive signature on the Declaration of Independence.

Every member of the Continental Congress who signed this document automatically became a criminal, guilty of sedition against King George III.

[47] In fact, Carroll had been appending "of Carrollton" to his signature for over a decade, the earliest surviving example appearing at the end of a September 15, 1765, letter to his English friend William Gibson.

Carrollton Manor was the name of a tract of more than twelve thousand acres in Frederick County, Maryland, which the Carroll family leased to tenant farmers.