90．Matching the influx of foreign immigrants into larger cities of theUnited States during the late nineteenth century was a domestic migration，from town and farm to city，within the United States．

(倒装句：Matching the influx…was a domestic migration…=a domestic migration…was matching the influx…)

19世纪晚期，与外国移民流入美国较大城市相媲美的，是美国本土移民从小镇和乡村到城市的国内迁移。

解析：

倒装，主干正常顺序是adomestic migration was Matching the influx of foreign immigrants….

从句1：from town and farm to city，

从句2：within the United States

从句1，2共同修饰主干中的a domestic migration