Are there accessible websites like the DAR has for other wars, War of 1812, Civil War etc.?

@Larry Mahar There are a few sites, depending on what information you are looking for.

Many War of 1812 pensions have been digitized and are available, free, on Fold3.
https://upfront.ngsgenealogy.org/2012/09/preserve-pensions-war-of-1812-digitized.html

For the Civil War, much depends on location. Many of the former Confederate states have their own state sites for Civil War pension information.

The National Park Service has a website indexing the names of former combatants. https://www.nps.gov/civilwar/soldiers-and-sailors-database.htm

Hope this helps.