I’m a Brit who lives in the US. Can confirm 99% of British people have never heard of the war of 1812, and even if they are a military history nerd and they have heard of it, they will consider it a minor sideshow to the main event of the era, which was Britain fighting France in the Revolutionary and Napoleonic wars from 1793-1815.
The US just wasn’t very important geopolitically 214 years ago. Sorry we burned y’all’s White House (ok not that sorry). Actually sorry we gave Andrew Jackson his opportunity to become famous by fighting a completely pointless battle after the war had already ended.