The Langdon family was part of the early wave of European settlers who arrived in New England in the 17th century, seeking new opportunities and religious freedom.

In the 17th century, the Langdon last name was particularly common in the southwestern counties of England, specifically in Cornwall and Devon.

Langdon's father was a prosperous farmer and local shipbuilder whose family had emigrated to America before 1660 from Sheviock, Caradon, Cornwall.

After finishing his primary education, he and his older brother, Woodbury Langdon, rejected the opportunity to join in their father's successful agricultural livelihood and apprenticed themselves to local naval merchants.

Four years later he owned his first merchantman and would continue over time to acquire a small fleet of vessels engaging in the triangle trade between Portsmouth, the Caribbean, and London.

British control of the shipping industries limited Langdon's business, motivating him to become a vigorous and prominent supporter of the colonial American revolutionary movement in the 1770s.

In 1774, he participated in the seizure and confiscation of British munitions from Fort William and Mary at Portsmouth harbor.

[2][dubious – discuss] Langdon was an ardent supporter of the drive to ratify the Constitution of the United States in New Hampshire.

He immediately wrote to George Washington to inform him that New Hampshire had become the ninth state which he described as the "Key Stone in the Great Arch.

He had many descendants, who in turn married into the high society of Argentina, such as the Saenz Valiente, Pueyrredon, Obarrio and Beccar Varela families.