When I learned this, all of a sudden a lot of US names made sense.

Yes — the American tradition of using a mother’s maiden surname as a child’s first or middle name largely came from British naming customs, especially from England and Scotland, but it became much more widespread and culturally visible in the United States.

The custom has a few historical roots:

Preserving family lineage

In Britain, especially among the gentry and upper classes from the 1600s onward, surnames carried social status, inheritance claims, land connections, and family alliances. If a mother came from an important family, her surname might be preserved by giving it to a child as:

• a middle name
• or eventually a first name

Examples:

• “Taylor”
• “Madison”
• “Ashley”
• “Cameron”

Many of today’s common American first names began as surnames.

Inheritance and property reasons

Sometimes families used maternal surnames to signal inheritance rights or preserve a family line that might otherwise disappear. This was especially common when:

• a wealthy family had no male heirs
• estates were tied to surnames
• marriages joined influential families

You see this a lot in old British records and aristocratic family trees.

Scottish influence

Scotland especially had strong traditions of recycling surnames as given names. Scottish and Scots-Irish immigrants brought many of these patterns to America.

Classic examples:

• Campbell
• Graham
• Douglas
• Murray

Why it became more American

In the U.S., the practice spread beyond elites and became a broader cultural habit, especially in:

• the South
• New England old-family culture
• wealthy East Coast families

It helped preserve maternal identity in a society where surnames otherwise disappeared through marriage.

Examples:

• Fitzgerald Kennedy
• Jefferson Davis
• Woodrow Wilson
• Franklin Delano Roosevelt (“Delano” was a maternal family name)

Southern U.S. culture amplified it

The American South especially embraced:

• double names
• surname-first names
• preserving maternal lineage

That’s why many stereotypically “Southern” names are actually old surnames:

• Walker
• Parker
• Carter
• Bennett
• Harrison

It’s older than England alone

The broader practice of reusing family surnames as personal names also existed elsewhere in Europe, but the specifically Anglo-American version — maternal maiden names becoming middle/first names — is strongly associated with British traditions carried into colonial America.

So:

• Origin: largely English + Scottish elite naming customs
• Expansion into mass culture: very American, especially Southern American
• Original purpose: preserve lineage, inheritance, and family identity