DNA, the Mexican-American War, and President Franklin Pierce

For over a quarter of a century, I chased a ghost in our family tree: the origins of our 2nd great-grandfather, Marcus Morton Pierce (1842–1882), whose short, tragic life left behind more questions than answers. Who were his parents? Where did the line originate?

Then, a breakthrough arrived via DNA.

A direct genetic match connected our branch to William Pearce (Pirce) (1770–1841), our 5th great-grandfather. That single link unlocked a paper trail going all the way back to 17th-century New England and our immigrant ancestor, Sergeant Thomas Pierce II (1608–1683).

Once the tree was fully built out, a fascinating historical discovery emerged: Sergeant Thomas Pierce II is also the 3rd great-grandfather of Franklin Pierce, the 14th President of the United States. That makes President Franklin Pierce our 4th cousin, 7 times removed—and reveals a striking wartime connection that may finally explain a family mystery nearly two centuries old.

Part 1: The Genealogical Bridge to President Franklin Pierce

Both our direct branch and the presidential line share a common foundation in colonial Massachusetts through Sergeant Thomas Pierce II. From there, the family tree split into two distinct New England legacies.

                    Sergeant Thomas Pierce II (1608–1683)

                     [10th Great-Grandfather / Common Ancestor]

                                      │

            ┌──────────────┴────────────┐

            │                                                   │

  Presidential Line                                       Our Direct Line

  ================                                       ===============

  Stephen Pierce (1651–1733)                             Thomas Pierce III (1645–1717)

  Stephen Pierce (1679–1749)                             Col. Timothy Pierce (1673–1748)

  Benjamin Pierce Sr. (1726–1764)                        Nathaniel M. Pierce (1701–1775)

  Gov. Benjamin Pierce (1757–1839)                       Jedediah Pierce (1746–1826)

  

  FRANKLIN PIERCE (1804–1869)                            William Pearce (1770–1841) [DNA Match]

  14th U.S. President & Brig. Gen.                       William Pearce (1794–1875)

                                                         James L. Pierce (1819–1847)

                                                         Marcus Morton Pierce (1842–1882)

                                                         Lillian Amanda Pierce (1867–1957)

Part 2: The Mystery of James L. Pierce & The Mexican-American War

For years, another shadow hung over Marcus Pierce’s story: What happened to his father, James L. Pierce?

We knew Marcus was raised without a father, recorded as a 7-year-old child in the 1850 U.S. Census. Records later confirmed that James L. Pierce (our 3rd great-grandfather) was born around 1819 in Foster, Providence, Rhode Island, and died at sea in 1847—at just 28 years old—en route to Mexico during the Mexican-American War.

Why did a young New Englander leave his wife and small child behind to march into a distant, tropical war zone?

The answer likely lies in the martial fervor sweeping New England at that exact moment—led directly by his cousin, Franklin Pierce.

Part 3: Brigadier General Franklin Pierce & The New England Brigade

Military service ran deep in the Pierce bloodline. Franklin Pierce was the son of Governor Benjamin Pierce, a celebrated officer of the American Revolution who had served under George Washington.

                   The 1847 Mexican War Connection

                   

 March 1847: Franklin Pierce commissioned Colonel (then Brig. Gen.)

   │   Rallies New England volunteers for the 9th U.S. Infantry

   ▼

 Spring 1847: James L. Pierce enlists & boards troop transport

   │   Departs for Mexico with New England regiment

   ▼

 1847: James L. Pierce dies at sea en route to Vera Cruz

   │

 August-Sept 1847: Brig. Gen. Pierce commands brigade at Mexico City

When Congress declared war on Mexico in May 1846, New England was initially reluctant to send troops. However, in early 1847, Congress authorized the creation of ten new regiments for the regular army, including the 9th U.S. Infantry Regiment—famously dubbed the "New England Regiment."

Franklin Pierce was appointed Colonel of the 9th Infantry in March 1847, quickly promoted to Brigadier General, and tasked with raising, organizing, and leading the New England brigade. A stirring orator and prominent public figure, Pierce rallied young men across Rhode Island, Connecticut, New Hampshire, and Massachusetts to join the crusade.

It is entirely plausible—and historically consistent—that young James L. Pierce answered his cousin's high-profile call to arms. Rallied by the family name and the promise of land and adventure, James signed on and boarded a troop transport ship bound for Vera Cruz.

Tragically, like thousands of soldiers in the Mexican-American War, James never saw the battlefield. Disease and fever ravaged the overcrowded transport ships in the Gulf of Mexico. James died at sea in 1847, leaving his young son Marcus to grow up fatherless back home in New England.

General Franklin Pierce survived the campaign, leading his brigade with bravery through the battles of Contreras and Churubusco before Mexico City, earning the fame that would carry him to the White House as the 14th President in 1853.

Conclusion: A Legacy Restored

It took a quarter-century of dead ends, a modern DNA match, and dusty 19th-century military rolls to piece this story together.

While history remembers Franklin Pierce as a Brigadier General, Governor’s son, and President of the United States, our own family record can now honor James L. Pierce—a young father from Rhode Island who gave his life at sea answering the call of duty, leaving behind a legacy that flows directly down to us today.

Thank you to Gemini AI for research assistance and narrative enhancement. — Drifting Cowboy

ALSO SEE “Cowboy Legacy -- The short, tragic life of Marcus Pierce”

https://a-drifting-cowboy.blogspot.com/2011/11/cowboy-legacy-short-tragic-life-of.html