2000
#11,827
National surname rank
Recorded bearers 2,426
First available Census row
Per 100,000 0.90
Rare Last name
Trosclair
A French occupational surname referring to someone who clears or cultivates land, derived from the Old French "trous cler".
According to the 2020 US Census Bureau surname tables, roughly 2,765 Americans carry the last name Trosclair. That puts it at #12,312 in the national surname ranking, appearing at a frequency of 0.81 per 100,000 people (about 1 in 123,962 residents).
This page is the full Name Census profile for the Trosclair surname. You will find the Census Bureau frequency data, a multi-census history view, an ancestry and ethnicity breakdown based on self-reported demographics, the name's meaning and origin where available, and answers to the most common questions people ask about this surname.
Bearers in the US
2.8K
1 in 123,962
Census rank
#12,312
2020 decennial data
Per 100,000
0.8
Frequency rate
Recorded bearers
2.4K
rare in the US
Popularity narrative
The Census Bureau recorded 2,411 bearers of the surname Trosclair in its 2020 decennial surname file. At a rate of 0.81 per 100,000 residents, it holds the 12312th position in the national surname ranking.
Among Census respondents with the surname Trosclair, the largest self-reported group is White at 81.0%. The next largest groups are Black (7.2%) and American Indian/Alaska Native (4.2%).
Origin
Meaning and origin of Trosclair
The surname TROSCLAIR is believed to have originated in France, specifically in the region of Brittany. It is thought to have emerged during the medieval period, around the 12th or 13th century.
The name TROSCLAIR is derived from the Breton words "tro," meaning "hamlet" or "small settlement," and "skler," meaning "clear" or "bright." This suggests that the name may have initially referred to someone who lived in a hamlet with a clear or bright location, perhaps near a lake or stream.
One of the earliest recorded instances of the surname TROSCLAIR can be found in the Armorial Général de France, a comprehensive register of coats of arms created in the late 17th century under the orders of King Louis XIV. This suggests that the TROSCLAIR family had achieved a certain level of prominence and recognition by that time.
In the 18th century, a notable figure with the surname TROSCLAIR was Jean-Baptiste TROSCLAIR, a French military officer who served during the American Revolutionary War. He was born in 1745 and fought alongside the Continental Army, playing a role in several key battles.
Another historical figure with the TROSCLAIR surname was Marie-Louise TROSCLAIR, a French author and poet who lived in the 19th century. She was born in 1820 and is known for her collection of romantic poetry published in 1855.
Closer to the present day, there was Henri TROSCLAIR, a French architect and urban planner who made significant contributions to the design and development of several cities in France during the early 20th century. He was born in 1878 and passed away in 1962.
Additionally, the TROSCLAIR name has been associated with the village of Trosclair, located in the department of Morbihan in Brittany, France. This village's name shares a similar etymology to the surname, further solidifying the connection between the name and the region.
Throughout history, the surname TROSCLAIR has been spelled in various ways, such as Trosclaire, Trosclere, and Troclaire, reflecting the linguistic and regional variations in Brittany and other parts of France.
Demographics
Ancestry and ethnicity for Trosclair
Among Census respondents with the surname Trosclair, the largest self-reported group is White at 81.0%. The next largest groups are Black (7.2%) and American Indian/Alaska Native (4.2%).
The bar chart below shows how Trosclair bearers described their own race and ethnicity on the 2020 Census form. The Census Bureau groups responses into six broad categories: White, Black or African American, Hispanic or Latino, Asian and Pacific Islander, American Indian and Alaska Native, and Two or More Races. When a category has too few respondents for a given surname, the Bureau suppresses the figure to protect individual privacy, which is why some names show fewer than six slices.
Percentages are shown for every Census year so the breakdown stays comparable over time. When the source file also includes raw headcounts, Name Census shows those alongside the percentages in the legend.
Keep in mind that these are self-reported numbers. A person's surname does not determine their race or ethnicity, and the distribution you see here reflects the specific population who happened to carry the Trosclair surname at the time of the 2020 Census, not any inherent property of the name itself.
- White81.0% · 1,952
- Black or African American7.2% · 174
- American Indian and Alaska Native4.2% · 101
- Hispanic or Latino3.6% · 88
- Two or more races3.6% · 88
- Asian and Pacific Islander0.3% · 8
Timeline
Historical Census data for Trosclair
Trosclair appears in 3 published Census surname files: 2000, 2010, 2020. The cards below show how the name's rank and bearer count changed across each release.
2010
#12,351
National surname rank
Recorded bearers 2,517
+91 bearers (+3.8%)
Per 100,000 0.85
Rank movement Down 524 places
2020
#12,312
National surname rank
Recorded bearers 2,411
-106 bearers (-4.2%)
Per 100,000 0.81
Rank movement Up 39 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #11,827 | 2,426 | 0.90 | First available Census row | First available Census row |
| 2010 | #12,351 | 2,517 | 0.85 | +91 bearers (+3.8%) | Down 524 places |
| 2020 | #12,312 | 2,411 | 0.81 | -106 bearers (-4.2%) | Up 39 places |
For 2020, the Census Bureau published race and Hispanic-origin columns as counts rather than percentages. Name Census converts those counts back into shares so the ancestry section stays comparable with the older surname files.
Year on year
2010 vs 2020 Census
How has the Trosclair surname changed between Census years? The chart shows bearer count side by side, and the table compares rank, count, and frequency.
Census year comparison
20102020
| Metric | 2010 | 2020 | Change |
|---|---|---|---|
| Rank | #12,351 | #12,312 | 0.3% |
| Count | 2,517 | 2,411 | -4.2% |
| Per 100K | 0.85 | 0.81 | -5.1% |
Between the 2010 and 2020 Census, the number of Trosclair bearers went from 2,517 to 2,411 (-4.2% change). The surname moved up 39 positions in the national ranking, going from #12,351 to #12,312.
FAQ
Trosclair surname: questions and answers
How many people in the U.S. have the surname Trosclair?
Name Census estimates that about 2,765 living Americans carry the surname Trosclair. Using the current population baseline, that works out to roughly 1 in 123,962 residents.
How common is Trosclair?
Trosclair ranks #12,312 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 0.81 per 100,000 residents, which is about 1 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 2,411 people with the surname Trosclair. That is different from the site's living-bearer estimate (2,765), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.81 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.81 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 1 of them to have the surname Trosclair.
Has Trosclair become more or less common over time?
Between 2010 and 2020, the surname Trosclair went from 2,517 recorded bearers to 2,411. That is a decrease of 106 (-4.2%). In the national ranking it rose from #12,351 to #12,312.
What does the Census say about the background of Trosclair?
Among Census respondents with the surname Trosclair, the largest self-reported group is White at 81.0%. The next largest groups are Black (7.2%) and American Indian/Alaska Native (4.2%). These figures come from the 2020 Census Bureau surname tables, based on how respondents described their own race and ethnicity.
Which group reports this surname most often?
White is the largest self-reported group for the surname Trosclair in the 2020 Census, accounting for 81.0% (1,952 people in the source table).
What is the full ancestry breakdown?
Trosclair appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (81.0%), Black (7.2%), American Indian/Alaska Native (4.2%). For 2020, the source file also published raw headcounts for each group, which is why this page can show both percentages and counts in the ancestry section.
Is this page using the latest Census data?
Yes. This page is using the latest surname file currently loaded on Name Census, which is 2020. The historical section above also keeps any older Census surname entries we have for Trosclair (2000, 2010, 2020).
Does the Census include every surname?
No. The Census Bureau only publishes surnames that appeared at least 100 times in a given decennial Census. That means very rare surnames are excluded entirely, and a surname can appear in one Census release but disappear from a later one if it falls below the reporting threshold.
Why don't the ancestry percentages always add up to exactly 100%?
There are two main reasons: rounding and suppression. The Census Bureau rounds published values, and it may suppress very small cells to protect privacy. For 2020, the Bureau also published raw group counts rather than direct percentages, so Name Census converts those counts back into shares for comparability across census years.
What does Trosclair mean?
A French occupational surname referring to someone who clears or cultivates land, derived from the Old French "trous cler". The fuller origin note on this page goes into more detail.
Where does the surname data come from?
All surname statistics on Name Census are drawn from the US Census Bureau's decennial surname frequency tables. These files list every surname that appeared 100 or more times in the 2020 Census, along with a count, a per-100,000 rate, and a self-reported demographic breakdown. You can read the full explanation on our methodology page.
How does Name Census estimate living bearers?
For surnames, Name Census does not age cohorts the way it does for first names. Instead, it takes the Census Bureau's published frequency for Trosclair (0.81 per 100,000) and applies that rate to the current U.S. resident population to estimate how many living Americans have the surname today.
How many people are called Trosclair?
Find out how many people are called Trosclair on our sister site HowManyOfMe.org — a quick modern estimate with the living-bearer count front and centre.