《汉书·志·地理志上》
景帝中二年开始筑城，迁徙万家人口到这裹，成为县。
景帝中二年初城，徙万家为县。
The construction of the city began in the second year of Emperor Jing, and 10,000 families were relocated here to become a county.
<s>[INST] Kindly elucidate the central themes in this passage in English: 景帝中二年初城，徙万家为县。 [/INST] The construction of the city began in the second year of Emperor Jing, and 10,000 families were relocated here to become a county.</s>
Kindly elucidate the central themes in this passage in English: 景帝中二年初城，徙万家为县。
user
The construction of the city began in the second year of Emperor Jing, and 10,000 families were relocated here to become a county.
assistant