Does anyone know where the fief of Sean in the Western Han Dynasty was?

Sean (250 years ago-before 185), whose real name was Liu Hou, posthumous title Wencheng, was the father of the city (now Bozhou, Anhui).

Look at the reliable official Sui Shu, volume 3 1, geography 26. Liu Pei originally belonged to Pengcheng County, which is very close to Bozhou City.

Henan is not the father of the city, but the father of the city. Also look at the official history: Hanshu Geography. The father city belongs to Yingchuan County. Serving the country before and staying in the country are two different things.