I went to Readex’s Early American Newspapers database for more information on this question. Its search function confirms that pickled olives weren’t advertised or widely discussed in America until after the Revolution, and then appear to have been a special import.
The only mention of “pickled olives” in American newspapers before independence is a 2 Apr 1767 item in the New York Gazette, reprinting a article in the Quebec Gazette, which in turn quoted from Henry Baker’s Employment for the Microscope, published in London in 1753. That quotation described treating a woman after accidental arsenic poisoning with an emetic, and it compared her resulting excrement to pickled olives.
In the 18 July 1785 Connecticut Courant, a Hartford merchant named Daniel Smith announced that he’d just put on sale a very wide assortment of imported goods, including “pickled Olives and Capers.” The 22 Dec 1788 State Gazette of South Carolina had an advertisement from the mercantile firm of Crouch and Trezevant offering, among other things, “Pickled Olives and Girkins.”
Finally, in the New York Daily Advertiser starting on 31 July 1797 the Coster brothers ran an ad about a ship just arrived from Bourdeaux. Among its goods were “pickled olives, capers anchovies.” That was during the decade when Martha Washington reportedly served pickled olives to Knox, Secretary of War.
In that same year, Samuel Deane of Bowdoin College published a book titled The New-England Farmer, or Georgic Dictionary, in which he encouraged American farmers to plant olive trees. “The oil and pickled olives brought from thence [Europe], amount to more than a trifle, which ought to be saved if practicable.” By that point pickled olives were clearly known in America, but Deane still had to argue that their import from Europe amounted to “more than a trifle,” so they probably weren’t widely consumed.