When the first settlers arrived in today's Terrebonne Parish area at the end of the 18th century, the land belonged to Spain. The Terrebonne area was considered part of Lafourche Interior. Several censuses were taken along Bayou Lafourche in the 1780's and 1790's. 
     Louisiana, which became U.S. territory in 1803, was first included in a Federal census in 1810. The Terrebonne Parish area was included in the Lafourche Parish section. The same thing happened in 1820. Terrebonne Parish was created in 1822 out of the southwest portion of Lafourche. The 1830 Terrebonne Parish census only contained the names of the heads of household and the numbers of males and females (in age groupings). The 1840 census was recorded in the same way. But in 1850 (and subsequent censuses), names and ages for all household members were recorded.

- The 1830 census has been printed in several quarterlies. Check out the Census portion of theAcadian-Cajun Genealogical Periodical Article Index. The names of the heads of household for that census are online.
- The 1840 census has been annotated and published by the Terrebonne Genealogical Society. I plan to post the heads of household for this census when I get the time.
- The 1850 census has been published by the Terrebonne Genealogical Society. Anyone want to volunteer to enter this census into computer format for me? The same goes for the remaining censuses.
- The 1860 census has been annotated and published by the Terrebonne Genealogical Society.
- The 1870 census has been published by the Terrebonne Genealogical Society.
- The 1880 census has been published by the Terrebonne Genealogical Society.
- The 1890 census was destroyed by a fire in Washington, D.C.  Ancestry.com is working on a census substitute for this census, utilizing other records of that time.
- The 1900 census has been published by Audrey Westerman.
- The 1910 census has been published by the Terrebonne Genealogical Society.