Researching The American Black Irish, by Blood

As we close up Irish American Heritage Month, we must be reminded that in America, it can be estimated that Black Americans have as much Irish ancestry as many White American that claim European admixture. 

This DNA, bloodline mixture, has historically created a shared history and cultural blending. We just no longer notice it due to time passed, melding of communities, and racial complexity that in America boils down to skin color. 

Most have not considered how Black American ancestry is an intricate and layered history, shaped by centuries of migration, forced displacement, enslavement, oppression, and resilience. From the transatlantic slave trade to the Civil Rights Movement, Black Americans have a unique lineage. This intertwines with the histories of multiple cultures, nations, and peoples. However, one facet of this heritage often goes unrecognized: the Irish connection within many Black American family trees.

Let's explore how Irish ancestry plays a significant role in the broader picture of Black American heritage. I've included a case study example here of Wm. O. Moseley of Hinds County, Mississippi, the father of seven mulatto children with enslaved Susan. This multi-year project yielded a will, names and description of the mulatto children, and their fate after being enslaved by their biological father. In this case, Dad, Wm. O Moseley, acknowledged them openly as early as 1840's.

The Irish-American Connection in Black American Ancestry
Throughout the 17th and 18th centuries, Irish indentured servants and enslaved Africans often lived in close proximity in the American colonies. In some cases, they worked side by side, sharing similar experiences of oppression. This is only one way Black American families often trace their Irish ancestry.  

I'm sure you know that before the cotton gin, miscegenation (marrying outside of one's race) was not illegal. Americans just got a bit dumber due to the need of free labor, so states began outlawing these unions. Children followed the mother's line. So if the mother was white, the children, even interracial children, had all of the same rights as their white mother.

Laws against interracial marriage, particularly between white women and Black men, were introduced gradually in the American colonies and later in U.S. states. These laws were part of broader racial segregation policies that intensified over time.

Plaçage and Miscegenation

Plaçage" refers to a historically recognized extralegal system in French and Spanish slave coloniesP, where white men entered into civil unions with women of African, Native American, or mixed-race descent, known as "placées," which were considered "left-handed marriages".

 
Plaçage was tolerated in colonial America, where European men, especially the French and Spanish, freely joined in civil unions with people of color. But later, this practice became frowned upon. Researchers will very often see these civil unions in the Louisiana Territory and Missouri Territory, but also noted in Illinois Country. Although this practice was once tolerated, new state laws against miscegenation may have forced otherwise white Americans to identify as black. Identifying as black would allow one to stay with their mixed-race family in the community where miscegenation was illegal. In addition to white men in civil unions with women of color, Paul Heinegg’s study identifies court documents where mixed-race children were born to free colored men and white women. These early practices can be seen from the Carolinas, Virginia, Maryland, to Delaware. Again, researchers may find proof of these unions in colonial and territorial records to include the Territory of Missouri

Colonial Period (Pre-1810)

Late 1600s – Early 1700s: The first laws banning interracial marriage (anti-miscegenation laws) emerged in the American colonies.

Virginia (1662): The first known law linking race and marriage. It stated that children of mixed-race unions would inherit the status of the mother (perpetuating slavery).

Maryland (1664): First colony to officially prohibit interracial marriage.

By the 1700s, most Southern colonies had similar laws, but enforcement varied. Some relationships, especially among lower-class whites and Black men, persisted despite these laws.

Post 1810 - Reconstruction Era
In the early 1800s, some states loosened their restrictions temporarily, but racial tensions, especially during and after Reconstruction (1865–1877), led to stricter enforcement and expansion of these laws.

Laws against interracial marriage, particularly between white women and Black men, were introduced gradually in the American colonies and later in U.S. states. These laws were part of broader racial segregation policies that intensified over time. 

• 1830s–1860s: More states enacted or reinforced bans on interracial marriage, particularly in the South.

• 1865–1877 (Reconstruction): Some interracial relationships became more visible, especially with freedmen, but backlash led to harsher laws.

• Late 19th century: The rise of Jim Crow laws firmly criminalized interracial marriage in the South.

We can turn to the compilation of historical documents and court extracts in the books of  author/researcher Paul Heinegg.

Many Irish men in the U.S. and the Caribbean fathered children with African and Black women. This was most often due to forced relationships. These mixed families resulted in a blending of cultures and lineages. As a result, many Black Americans have Irish DNA in their heritage, a fact that is becoming more visible thanks to advancements in DNA testing.

When He Acknowledges His Mulatto Children

His own mulatto children were emancipated and educated in Ohio
The Southron, Jackson, Mississippi, 10 Dec 1846, Page 3

One of the a3Genealogy most interesting cases was that of wealthy "slave trader" William O. Moseley of Mississippi, who fathered seven children with an "enslaved" women. 

While living, he transported his eldest children, granted them their freedom using name and description in court records.

Emancipation of Mulatto children with Descriptions: full siblings Douglas and Madora

He also had his sons educated at Oberlin College, and his daughters, too, were educated and had home training in Ohio.

In 1870, when the children all returned home, his mulatto daughter Madora and family lived on the land with father Wm. O. Moseley.

In his will he acknowledged the mulatto children that was "begotten by" him.

His sister and brother was a witness to the will and courts. His eldest son, was the administrator. He had no other children and never married a white woman.

His eldest became a Representative for the State of Mississippi.

George G. Moseley, Hinds County Representative, 1874 -1875

The Role of DNA Testing
With the rise of DNA testing, Black Americans are increasingly discovering Irish roots that were previously hidden or forgotten. For example, a family that may have long identified as purely African American may find that they share genetic markers that trace back to Ireland. These discoveries are part of a broader movement to uncover the complex histories of Black Americans and reveal the diverse ethnic and cultural backgrounds that make up their identity.

Of course this phenonomen goes both ways. Be sure to read Why Would White Ancestors Identify as Black? 

Other Cited resources: 

• Sean O’Callaghan, To Hell or Barbados: The Ethnic Cleansing of Ireland (Dingle: Brandon Books, 2000).
• Noel Ignatiev, How the Irish Became White (New York: Routledge, 1995).
• Tyler Anbinder, Five Points: The 19th-Century New York City Neighborhood That Invented Tap Dance, Stole Elections, and Became the World’s Most Notorious Slum (New York: Plume, 2002).
• Katarzyna Bryc et al., “The Genetic Ancestry of African Americans, Latinos, and European Americans across the United States,” The American Journal of Human Genetics 96, no. 1 (2015): 37–53, https://doi.org/10.1016/j.ajhg.2014.11.010.

While these revelations can be surprising, they also remind us of the interconnectedness of history.

Kathleen Brandt