What was the nickname given to the time. In American history that started in 1965 and ended in 1900?

the gilded age
the roaring 20s
the golden age
the middle ages

Are you sure 1965 is right?? Could it be 1865? I think you are looking for the Gilded Age from late 1860s to 1900.

Explanation:

(202 bc - 220 ad) dynasty started by lui bang; a great and long-lasting rule, it discarded the harsh policies of the qin dynasty and adopted confucian principles; han rulers chose officials who passed the civil service exams rather than birth; it was a time of prosperity