An attempt has been made to identify all the Adamthwaites who appear in the censuses of England, Wales and Scotland taken in 1841, 1851, 1861, 1871, 1881, 1891, 1901 and 1911 and all available censuses in USA and Canada, plus electoral rolls in Australia. This has proved a more difficult task than you would imagine, due to the highly imaginative ways in which the name 'Adamthwaite' has been transcribed!
The tables on the linked pages show the names as transcribed by Ancestry, so if you are searching that site for any of the entries, make sure you spell the surname as it has been transcribed, errors and all. IMPORTANT NOTE: These are big files, so may take some time to download on dial-up connections, please be patient. You can enlarge the size of each table with the magnification tool on the Adobe reader browser. Most of the tables spread over three or four pages, so you will need to scroll down and across.
On all tables (except those for USA and Canada), the colour scheme adopted is an attempt to group members of each of the known lines of the Adamthwaite families together, using the system described here (unshaded families have not been allocated to any branch yet - if YOU know where they belong, please let me know):