▁late ▁ 1 9 th ▁century ▁have ▁written ▁detailed ▁histor ies ▁of ▁their ▁own ▁cities . ▁Academ ic ▁interest ▁began ▁with ▁Arthur ▁Schles inger , ▁Sr . ▁at ▁Harvard ▁in ▁the ▁ 1 9 2 0 s , ▁and ▁his ▁successor ▁Oscar ▁Hand lin . ▁ ▁The ▁" new ▁urban ▁history " ▁emer ged ▁in ▁the ▁ 1 9 6 0 s ▁as ▁a ▁branch ▁of ▁Social ▁history ▁seeking ▁to ▁understand ▁the ▁" city ▁as ▁process " ▁and , ▁through ▁quant itative ▁methods , ▁to ▁learn ▁more ▁about ▁the ▁in art ic ulate ▁masses ▁in ▁the ▁cities , ▁as ▁opposed ▁to ▁the ▁may ors ▁and ▁el ites . ▁Much ▁of ▁the ▁attention ▁is ▁devoted ▁to ▁individual ▁behavior , ▁and ▁how ▁the ▁inter ming ling ▁of ▁classes ▁and ▁eth nic ▁groups ▁operated ▁inside ▁a ▁particular ▁city . ▁Sm aller ▁cities ▁are ▁much ▁easier ▁to ▁handle ▁when ▁it ▁comes ▁to ▁tracking ▁a ▁sample ▁of ▁individuals ▁over ▁ten ▁or ▁ 2 0 ▁years . ▁ ▁Common ▁them es ▁include ▁the ▁social ▁and ▁political ▁changes , ▁exam in ations ▁of ▁class ▁formation , ▁and ▁ra cial / eth nic ▁t ensions . ▁▁ ▁A ▁major ▁early ▁study ▁was ▁Ste phan ▁Th ern st rom ' s ▁P over ty ▁and ▁Progress : ▁Social ▁M ob ility ▁in ▁a ▁Nin ete enth ▁Century ▁City ▁( 1 9 6 4 ), ▁which ▁used ▁census ▁records ▁to ▁study ▁New bury port , ▁Massachusetts , ▁ 1 8 5 0 - 1 8 8 0 . ▁A ▁sem inal , ▁land