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The alliterative phrase the cream of the crop, and its variants, designate:
– (literally): the best produce from a harvest;
– (figuratively): the best of a group of people or things.
In the phrase the cream of the crop, the noun cream is used figuratively in the sense of: the most excellent element or part.
—Cf. the phrase crème de la crème, which designates the best people in a group, or the best type of a particular thing.
These are, in chronological order, the earliest occurrences of the phrase the cream of the crop and variants that I have found:
1-: From a letter to the Editor, by ‘T.’, in “reply to W. W. on folding sheep on turnips”, published in Evans and Ruffy’s Farmers’ Journal, and Agricultural Advertiser (London, England) of Monday 24th November 1828 [page 1, column 4]:
A flock of fattening Wethers ought not to be subject to the same limits of diet, as a store flock. The usual plan is, for sheep like these to skim the cream, as it were, of the crop, and for the flock (by which is meant the ewes and store sheep) to follow, and eat up what their betters have left.
2-: From the following advertisement, published in The New York Herald (New York City, New York, USA) of Friday 17th May 1844 [page 3, column 3]:
SEGARS—HABANEROS’ HOUSE, 12 BEEKMAN St.—Don Julian de Rivas, of Havana, invites the lovers of good segars to call as above, or at 93 Beaver st., a few doors from the four corners of Wall and Pearl sts., and give a trial to the fragrant and self-puffing segars he has had sent by his brother, Don F. These segars under the brand of “Figaro,” are the cream of the last crop, and calculated to bring the brand above all other brands. PENA & RIVAS, Jr Sole Agents.
3-: From Present and Prospective Condition of the Cotton Market.—No. 3., by ‘a cotton manufacturer’, published in The Boston Daily Atlas (Boston, Massachusetts, USA) of Thursday 6th March 1851 [page 2, column 4]:
Our manufacturers avoid not only the low sorts, but the ordinary kinds, in which is comprised a large portion of the crop, on the ground that their customers require goods made of the best cotton, the cream of the crop.
4-: From Horticulture. Written expressly for Bell’s Weekly Messenger, published in Bell’s Weekly Messenger (London, England) of Saturday 23rd July 1853 [page 6, column 1]:
Since the period of last week at which our usual article was written, those terrific falls of rain have occurred which have been attended with such disastrous results to the farmer, and have also left unmistakable traces of their presence and force in the domain of the gardener. The bloom of the roses has been fairly washed off, and the various occupants of the flower garden have been sadly battered; while in the kitchen garden beds of ripe strawberries have been wholly spoiled, and the cream of the raspberry crop unfitted for preserving purposes.
5-: From District News. Caputh.—The Weather and Harvest, published in The Perthshire Advertiser, and Strathmore Journal (Perth, Perthshire, Scotland) of Thursday 7th October 1858 [page 3, column 4]:
Some of the farmers here have finished potato lifting; others are busily engaged in taking them from the soil. In most cases, the crop is more abundant than it has been for the last few years; but that mysterious visitor, the disease, seems to have received an extensive commission this season, as on some farms here not less than the half are tainted, while on others there is even more; and to add to the disaster, it is the very cream of the crop that is selected by the destroyer.
6-: From the Hartford Daily Post (Hartford, Connecticut, USA) of Wednesday 12th January 1859 [page 2, column 1]—the “elder neighbors” refers to the Hartford newspapers such as the Hartford Daily Courant that were founded before the Hartford Daily Post was:
The Post has walked over a field which our elder neighbors had appropriated to themselves—and, worst sin of all—it has gathered the cream of the crop. In a word, we have trodden upon our neighbors’ sensitive toes. It is useless for us to remind them that the enclosures are dilapidated and the field open; they look upon us as intruders, and, but for their impotency, would expel us.
7-: From “an extract from W. P. Wright & Co.’s circular, forwarded by the last steamer of the 25th ult. for Liverpool”, published in the New Orleans Daily Crescent (New Orleans, Louisiana, USA) of Friday 4th February 1859 [page 7, column 5]:
The cotton market in this city, during the past week, has suddenly shown symptoms of animation and vigor […]. There appears to have been an impulse given to the power of consumption in other countries than Great Britain, judging from the quantity already exported and taken by our own manufacturers, as well as from the demand which still exists in all the markets of the South. The cream of the crop has been secured for France, the Continent, and our own mills.