The Hangul Jamo block spans U+1100–U+11FF, 256 codepoints in Plane 0 (Basic Multilingual Plane). Every one of them is assigned in Unicode 16.0.
All of its characters belong to the Hangul script.
By general category: 256 other letters (Lo).
The first 240 arrived in Unicode 1.1 (1993); later additions came in 5.2 (16).