Apple-Pie Order

“Apple-pie order” means that things are in perfect order. The term “apple-pie order” dates to at least the 1776, but its origin is uncertain. Cap-à-pie (armed from head to foot) and nappe plié (French for “folded linen”) have both been suggested as origins.
 
The 1764 citation (below) of “mince-pye order” is also of unknown origin.
     
 
Infoplease
Apple-pie Order
Prim and precise order.
 
The origin of this phrase is still doubtful. Some suggest cap-à-pie, like a knight in complete armour. Some tell us that apples made into a pie are quartered and methodically arranged when the cores have been taken out. Perhaps the suggestion made above of nap-pe-pli (French, nappes pliées, folded linen, neat as folded linen, Latin, plico, to fold) is nearer the mark.
 
It has also been suggested that “Apple-pie order” may be a corruption of alpha, beta, meaning as orderly as the letters of the alphabet.
 
“Everything being in apple-pie order, ... Dr. Johnson ... proposed that we should accompany him ... to M’Tassa’s kraal.” —Adventures in Mashonaland, p. 294 (1803).
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
     
Wiktionary: apple-pie order
Etymology
French nappe (“‘linen’”) plié (“‘folded’”) + order
Noun
apple-pie order (uncountable)
1. extremely neat and tidy; everything organized as it should be
References
Partridge, Dictionary of Slang, 7th Ed.
 
(Oxford English Dictionary)
apple-pie order n. perfect order or neatness.
[The motivation for the expression is unclear. It has been suggested that it shows a folk-etymological alteration of various different expressions (e.g. a supposed *Cap-a-pie order, or French nappes pliées (see apple-pie bed n.)), but none of these is supported by any documentary evidence.]
1780 T. PASLEY Jrnl. 12 May in Private Sea Jrnls. (1931) 87 Their Persons Clean and in *apple-Pie order on Sundays.
1813 SCOTT in J. G. Lockhart Life (1839) IV. 131 The children’s garden is in apple-pie order.
1834 F. MARRYAT Jacob Faithful I. viii. 142 Put the craft a little into apple-pie order.
1904 J. LONDON Sea-wolf xi. 103 The boat-pullers and steerers have..put their boats in apple-pie order.
1994 Eng. Hist. Rev. 109 1225 For Mann, history is ‘a patterned mess’, not something reducible to apple-pie order.
   
Google Books     
June 1764, The Critical Review, pg. 479:
After all (to do our author justice) he shews himself a sufficient master of address by the mince-pye order in which he serves up his entertainment, which is sometimes so disguised, that at first we cannot discover the original ingredients.
     
5-8 October 1776, London (UK) Chronicle, pg. 343, col. 1:
Things are amazingly altered; decorum is the word; we are all drilled, rank and file; the new Captain keeps the very ladies in apple-pye order; ...
     
25 September 1783, Morning Chronicle and London Advertiser<.i>

(London, UK), pg. 3, col. 2:
HUMBUG THE SECOND.
Charing-Cross, 23d September, 1783.
(...)
... every thing was in apple-pye order in a hurry, for a little bund e-tail was determined to shew off upon the occasion, as our cousins were to be sent off for to see the raree show.
 
22 January 1784, The Maryland Gazette (Annapolis, MD), pg. 1, col. 3:
HUMBUG THE SECOND.
Charing-Cross, 23d Sept. 1783.
(...)
... every thing was in apple-pye order in a hurry, ...
 
Google Books
The Sporting Magazine; or Monthly calendar of the transactions of the turf
1793
Pg. 30:
There everything was in apple-pie order, under the superintendence of Bui, his head groom and jockey, a half-caste, whom some of his good-natured friends…
   
Google Books
January 1809, Edinburgh Review, pg. 417:
The first, however, could the better be dispensed with, as every thing was, to use a vulgar phrase, in apple-pye order ; and a hungry man, we may imagine, could in those days dine without music, and even without hearing grace.
 
Google Books
The Dialect of Craven:
In the West-Riding of the county of York

By William Carr
London: William Crofts
1828
Vol. I
Pg. 9:
APPLE-PIE-ORDER, Any thing in very great order.
 
Google Books
An essay on the archaeology of our popular phrases, and nursery rhymes
Vol. II
By John Bellenden Ker
London: Longman, Rees, Orme, Brown, Green & Co.
1837
Pg. 44:
IN APPLE-PIE ORDER.
A homely, but old and well knwon, expression for the exact [due] state of the object in question; each thing in its proper place; all exactly as it should be. In happe el bij hoord er; q.e. in the event [which has taken place] another hand has interferred; that which has happened has another cause than what appears upon the face of it; implying, all that happens is a part of the universal system of a directing providence. That whatever happens is destined by him who provides all. Inferring there is no such thing as chance [effect independent of cause] however it may seem to him who looks no further than upon that which has taken place, and regards it merely in relation to the event in question]. From which it is to be inferred all which happens is a providential pre-arrangment; and is no other than as the self-readjusting system of equivalents, universally admitted in the system of physics in relation to the heavenly bodies. By the travesty sense of, all in order in a shop [a house] or any other smaller concern within the scope of hourly observation, In, in. Happe, happening, an event, an instance of happen, to take hold, to seize, to snap up, and thus to take [seize] and, in idea, to stop [for the moment] time in its course; and happe, is but as the moment [period] of time the event in question takes [took] place. hence the frequentive happenen and our to happen, as well as happy and happiness, terms implying moments properly (Pg. 45—ed.) seized and used, and what else as happiness. El, elsewhere, another. Bij, in the power of. Hooren, to belong to, to be the right (property) of. Er, there. B, and p, intermuting sounds. H no letter, and happe el bij hoord er sounds apple pye order, by omitting the two aspirates.
     
Google Books
Dictionary of Americanisms:
A glossary of words and phrases, usually usually regarded as peculiar to the United States.

By John Russell Bartlett  
New York
1848
Pg. 12:
APPLE-PIE ORDER. An expression used in familiar conversation, denoting perfect order. It is used alike in England and America. — Halliwell’s Dict’y.
 
OCLC WorldCat record
Apple-pie order : a story for the young.
Publisher: London : T. Nelson & Sons, [ca.1850]
Edition/Format: Book : Juvenile audience : English
 
Google Books
Glossary of Northamptonshire words and phrases
By Anne Elizabeth Baker
London: J. R. Smith
1854
Pg. 16:
APPLE-PIE-ORDER. A very common phrase expressive of great nicety an exactness. To have every thing in apple-pie-order, is to be particular and precise in personal appearance and domestic arrangements.
   
Google Books
Milledulcia: A thousand pleasant things
By Notes and queries
New York, NY: Appleton
1857
Pg. 290:
Cap-a-pie, armed from head to foot: this has given rise to the homely term of apple-pie order.
 
Google Books
The Slang Dictionary:
or, The vulgar words, street phrases, and “fast” expressions of high and low society

By John Camden Hotten
London: James Camden Hotten, Piccadilly
1865
Pg. 68:
APPLE-PIE ORDER, in exact or very nice order.
 
Google Books
Collections Historical & Archaeological Relating to Montgomershire and Its Borders
Vol. III
London: Thomas Richards
1875
Pg. 354:
Imple order, perfect order, everything clean and in its proper place. “The maister gets into sich a towering passion, if everything is’nt in imple order.”
 
Another form of “imple order” is “ample order”, and even “apple-pie order” is often heard, but what kind of order “apple-pie order” is, the writer is quite unable to say.
   
Google Books
The Leisure Hour
1880
Pg. 192:
The saying, “To have everything in apple-pie order, ” is supposed to have its origin from the following circumstance. It was the custom many years ago to take off the top crust of an apple-pie and mash up the fruit with sugar and cream, then cut the crust into triangular pieces and stick them end downwards into the fruit in various patterns, as circles, crowns, stars & c.