Gild·ed Age 
(g
ĭl
d
ĭd)
n. The period in American history from about 1870 to 1900, during which rapid industrialization, a labor pool swelled by immigration, and minimal governmental regulation allowed the upper classes to accumulate great wealth and enjoy opulent lifestyles.
[After the 1873 novel The Gilded Age: A Tale of Today by Mark Twain and Charles Dudley Warner (1829-1900), American author.]