The right to privacy was in fact a prominent theme in the days of the American Revolution, when the British government would quarter troops in American houses at the expense of the Americans. This was acknowledged in the Declaration of Independence [1]: "He has kept among us, in times of peace, Standing Armies without the Consent of our legislatures." To protect against these ills, the 1787 Constitution included the third and fourth amendments[2]: "No Soldier shall, in time of peace be quartered in any house, without the consent of the Owner, nor in time of war, but in a manner to be prescribed by law.

"The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized."

While these measures did not at first apply to blacks[3], the fourteenth amendment was written after the Civil War to ensure that all members of society would have those rights.

What the founders did not anticipate was the advent of the camera, which revolutionized the concept of privacy. One could not be punished for betraying and slandering a neighbor, due to the First Amendment freedom of speech provisions, but once the camera came around, the existing law could not punish people who took pictures of other people without their consent and in well, not-so-savory situations. This was a concern to then-to-be Supreme Court Justice Louis Brandeis, who in 1890 published the work The Right To Privacy [4] in which he argued, “These considerations lead to the conclusion that the protection afforded to thoughts, sentiments, and emotions, expressed through the medium of writing or of the arts, so far as it consists in preventing publication, is merely an instance of the enforcement of the more general right of the individual to be let alone. It is like the right not to be imprisoned, the right not to be maliciously prosecuted, the right not to be defamed. In each of these rights, as in all other rights recognized by the law, there inheres the quality of being owned or possessed - and (as that is the distinguishing nature of property) there may be some propriety in speaking of these rights as property.”

When Brandeis took the bench, his ideas did not quickly gain popularity, but he did manage to make a statement on a few occasions. Perhaps the most famous instance of this was Olmstead v. United States, when Brandeis wrote [5] of the founders in his dissenting opinion, "They sought to protect Americans in their beliefs, their thoughts, their emotions and their sensations."

Brandeis' ideas would be directly affirmed 26 years after his death in the landmark case Katz v. United States, which overturned Olmstead v. United States. Justice Potter Stewart delivered the opinion of the court, with this direct reference to Brandeis[6]: "But the protection of a person's general right to privacy-his right to be let alone by other people -is, like the protection of his property and of his very life, left largely to the law of the individual States."

TL;DR: Privacy was a big thing in the early days of the US but the concept was single-handedly expanded by a man named Brandeis.

[1] Declaration of Independence. Jefferson, Thomas et al. 1776. [2] Constitution of the United States. Amendments III; IV. 1787. [3] Acts and Resolutions of the State of Florida. Chapter 87. Approved January 6, 1847. [4] The Right To Privacy. Brandeis, Louis. Harvard Law Review. 1890. p. 205. [5] Louis Brandeis dissenting opinion in Olmstead v. United States; 277 U.S. 438. 1928. [6] Potter Stewart Opinion of the Court in Katz v. United States; 389 U.S. 347. 1967.