In 1870-72, John Marius Wilson's Imperial Gazetteer of England and Wales described Southwick like this:
SOUTHWICK, a tything in North Bradley parish, Wilts; 2½ miles SSW of Trowbridge. Real property, £4,711. Pop., 1,241. Houses, 279. There are a church, a Baptist chapel, and a Methodist chapel.
A Vision of Britain through Time includes a large library of local statistics for administrative units. For the best overall sense of how the area containing Southwick has changed, please see our redistricted information for the modern district of West Wiltshire. More detailed statistical data are available under Units and statistics, which includes both administrative units covering Southwick and units named after it.
GB Historical GIS / University of Portsmouth, History of Southwick in West Wiltshire | Map and description, A Vision of Britain through Time.
Date accessed: 13th December 2013
Click here for more detailed advice on finding places within A Vision of Britain through Time, and maybe some references to other places called "Southwick".