The era when trireme supremacy meant regional hegemony came to an end not long after that.
Very few American Southerners were members of vigilante groups like the Ku Klux Klan during the era of segregation.
At least by anecdote, they are less common now in an era hyperconscious of harassment.
In a weird way it felt like the end of an era—and obviously, the beginning of a new one.
I think many readers found an entry to your work with your Civil War–era novel Woe to Live On.
It was about this era that the Comacines began their many emigrations, and spread throughout Italy.
At that time the country was emerging from the era of straggling settlers.
The era of "social unrealities," to use the trenchant phrase of Daniel, had come.
It commences with a sentence which is subtle enough for the nineteenth-century era.
One would say rather that they recalled something of primitive science and of the era of intuition.
1716, earlier aera (1610s), from Late Latin aera, era "an era or epoch from which time is reckoned," probably identical with Latin aera "counters used for calculation," plural of aes (genitive aeris) "brass, copper, money" (see ore, also cf. copper).
The Latin word's use in chronology said to have begun in 5c. Spain (where, for some reason unknown to historians, the local era, aera Hispanica, began 38 B.C.E.; some say it was because of a tax levied that year). Like epoch, in English it originally meant "the starting point of an age;" meaning "system of chronological notation" is c.1640s; that of "historical period" is from 1741, e.g. the U.S. Era of Good Feeling (which was anything but) in reference to the Monroe Administration (1817-24), attested from 1817.
Synonym epoch. Webster's Unabridged makes these words almost synonymous, but "era" usually connotes a span of time rather than a point in time.