When did christopher columbus happen

What is zinn's approach to the study of history? what does he suggest occurs when history is told is the story of human progress?

“[the city’s engineers excelled in areas] neglected by the greeks, such as the construction of roads and aqueducts, and of sewers that could wash the filth of the city into the tiber. they have built paved roads throughout the country, leveling ridges and filling up hollows, so as to make possible the movements of heavily loaded wagons. . and such is the quantity of water brought in by the aqueducts, that veritable rivers flow through the city and its sewers: almost every house has cisterns, waterpipes, and copious fountains.” —strabo, as quoted in empires ascendant: time frame 400 b. c.–a. d. 200 cisterns are tanks that hold water until it is needed; if a house has a cistern, it is likely to also have a. aqueducts. c. a swimming pool. b. a fish pond. d. sinks and faucets.

In the latter stages of the civil war who was given the responsibility of winning the war for the north