1640s, from French coup d'étate, literally "stroke of the state" (see coup). Technically any sudden, decisive political act, especially an important and unexpected change in the form and methods of a government, but in 20c. popularly restricted to the overthrow of a government.
1772, from tea + party (n.). Political references to tea party all trace to the Boston tea party of 1773 (the name seems to date from 1824), in which radicals in Massachusetts colony boarded British ships carrying tea and threw the product into Boston Harbor in protest against the home government's taxation policies. It has been a model for libertarian political actions in the U.S. (generally symbolic), including citizen gatherings begun in early 2009 to protest government spending.
coined 1866 by Thoreau as the title of his essay originally published (1849) as "Resistance to Civil Government."
If the alternative is to keep all just men in prison, or give up war and slavery, the State will not hesitate which to choose. If a thousand men were not to pay their tax-bills this year, that would not be a violent and bloody measure, as it would be to pay them, and enable the State to commit violence and shed innocent blood. This is, in fact, the definition of a peaceable revolution, if any such is possible. [Thoreau]
"the press," by 1824, and especially from 1831, British English. For the other three, see estate. Earlier the term had been applied in various senses that did not stick, including "the mob" (1752), "the lawyers" (1825). The extension to the press is perhaps an outgrowth of the former.
Hence, through the light of letters and the liberty of the press, public opinion has risen to the rank of a fourth estate in our constitution; in times of quiet and order, silent and still, but in the collisions of the different branches of our government, deciding as an umpire with unbounded authority. ["Memoir of James Currie, M.D.," 1831]
[Newspapers] began to assume some degree of political importance, during the civil wars of the seventeenth century, in England; but it is not until within the last fifty years that they have become, — as they are now justly styled, — a Fourth Estate, exercising a more powerful influence on the public affairs of the countries in which they are permitted to circulate freely, than the other three put together. [Alexander H. Everett, "Address to the Phi Beta Kappa Society of Bowdoin College," 1834]
severe Puritanical code said to have been enacted mid-17c. at the founding of New Haven and Connecticut colonies, 1781; of uncertain signification, perhaps from the notion of coldness, or from one of the figurative senses in blue (adj.1). Blue was the color adopted by 17c. Scottish Covenanters (in contradistinction to the royal red) and hence the color for a time acquired an association with strictness in morals or religion. Or perhaps connected to bluestocking in the sense of "puritanically plain or mean" (see bluestocking, which is a different application of the same term); the parliament of 1653 was derisively called the bluestocking parliament.
The assertion by some writers of the existence of the blue laws has no other basis than the adoption by the first authorities of the New Haven colony of the Scriptures as their code of law and government, and their strict application of Mosaic principles. [Century Dictionary]
Long, detailed lists of them often are given, but the original reference (in an anonymous history of Connecticut printed in London during the Revolution) says they were so-called by the neighboring colonies, "were never suffered to be printed," and then gives its own long list of them in quotations. The common explanation (dating to 1788) that they were written on blue paper is not now considered valid.