Why is the phrase "cake walk" informally used to describe an easy to achieve task, while its origin says a different story?
Solution 1:
Here is the entry for cakewalk as a noun in J.E. Lighter, Random House Historical Dictionary of American Slang (1994):
cakewalk n. Orig, Boxing. an easy victory; (hence) an easy task. [First six cited instances:] 1877 D. Braham Walking for Dat Cake (pop. song title). 1897 Siler & Houseman Fight of the Century 46: It's a cake-walk for Jim...Fitz hasn't a chance. 1898–1900 Cullen Chances 53: It's a cake-walk fo' dat baby. 1910 N.Y. Eve[ning] Jour[nal] (Feb. 7) 10: Joe is the Marathon Kid and Samuel would be a cakewalk. 1916 in OEDS I 414: A fight that would not be a cakewalk. 1925 Fraser & Gibbons Soldier & Sailor W[or]ds 43 {ref. to WWI}: Cake Walk, A: an easy task.
Lighter is interested in the word as a slang term, not in its original, literal sense.
Early newspaper notices of 'cake-walks'
A search of the Elephind newspaper database finds instances of cake-walk in its original sense going back to 1870. An excellent description of an early cakewalk appears in "A Negro Festival: The 'Cake Walk' at Mount Vernon,'" in the New-York Tribune (July 20, 1870), beginning with this somewhat iffy historical note:
...for Mount Vernon has its "Cake Walk," a festival most unique and most entertaining. This fête is, I believe, peculiar to the colored race, and although there nay exist no written record of its history or of its origin it has been faithfully handed down among the traditions of the past from generation to generation, by sable grandmothers, until in our own day it has suddenly sprung up again in our little village.
and culminating in this description of the competition itself:
Upon long tables were placed a number of cakes with other refreshments. The largest of the cakes were those destined as prizes to the successful walkers. The dark beauty who should be adjudged the best promenader was to receive the largest cake; the one who made the next best display would carry off the second cake in size—and so on. ...
Loud clapping of hands, and even cheers, greeted them [three young women] as they started upon their expedition, which was to be three times around the room. Long and rapid were the strides of the tall maiden; short and breathless the quick stepping of the stout one; and easy and graceful the footfalls of the little one. Faster and faster they went, making no endeavor to keep step; flounces flew, and ribbons fluttered strangely—dark eyes flashed, and cheap jewelry glittered in the gas-light, as the aspiring three hastened around the hall, each one proudly expectant of winning the first cake. However, the trial was not for speed, but to see which one excelled in the fine art of walking; which one carried her head and shoulders erect; which one turned her toes out; and which one knew how to manage her arms and hands gracefully. All of these points were both gravely and comically discussed, and decided upon by the spectators.
A number of other announcements of cakewalks appear from 1874 onward. From an untitled item in the Huntingdon [Pennsylvania] Journal (March 18, 1874):
The festival and "cake walk" held in the Court House, last week, by the colored folks, was a success. They request us to return thanks to the public.
From an untitled item in the [Austin, Texas] Intelligencer-Echo (March 1, 1875):
A congregation at Utica, N. Y., proposes to hold a cake-walk and neck-tie festival to raise 200 to pay its retiring minister's salary. The services which cannot be compensated without a cake-walk and neck-tie festival must indeed be poorly esteemed.
From an untitled item in the [Hillsboro, Ohio] Highland Weekly News (June 14, 1877):
The Colored Baptist Church will hold a Picnic on Thursday, June 21, and a Festival and Cake-Walk at night, in City Hall. Proceeds for the benefit of the church. Everybody invited to attend.
From an advertisement in the New York [City] Clipper December 22, 1877):
GILMORE'S GARDEN, COMMENCING MONDAY EVENING, DEC . 17, GRAND NATIONAL COLORED JUBILEE AND BABY-SHOW, THE FIRST EVER HELD IN NEW YORK, CONTINUING ONE WEEK, and winding up with a regular "OLE VIRGINNY" CAKE-WALK. THE GREATEST NOVELTY OF TUE AGE! The exhibition of Colored Infants will be open every day after Monday, from 1 to 4 and from 7 lo 10 P. M. The whole in conjunction with THE GREAT LONDON CIRCUS[.]
Elsewhere in the same issue of this newspaper the following item appears under the headline "City Summary":
The London Circus enters upon the tenth week of a remarkably prosperous season on Dec. 17. The extra attractions announced for this week are a colored baby-show, and, on Saturday night next, an old Virginia cake-walk. All the specialties of the circus company will be continued, and matinees are to be given dally until the close of the season, Dec. 31.
As for what exactly an "old Virginia cake-walk" entailed, this follow-up item in the "City Summary" section of the New York Clipper (January 5, 1878) indicates that it involved couples rather than single women (as in the Mount Vernon cakewalk of 1870), but that it remained a walking contest:
A Virginny cake-walk at Gllmore's Garden on the night of Dec. 29 attracted a large attendance. Ten couples contended for the prizes, consisting of a gold watch, a cake containing a $20 gold piece, and a gold-mounted ebony cane. Frank Whittaker officiated as master of ceremonies, and received a cordial welcome as he entered the arena. In a vein of pleasantry he addressed each couple as they started upon their competitive walk, and later, in presenting some of the ladies with bouquets sent from the auditorium by admirers, his felicitous speeches elicited the applause of the audience. The best walkers were received with the usual marks of approbation, commingled with cheers and waving of handkerchiefs, and were recalled after the termination of their walk. The prizes were presented in the arena, Francis Griggs and Mme. Ray winning the watch, Miles Butler the gold-headed cane, and George Bay and Mrs. Hyatt the cake. Mrs. Bowser, one of the "cleaners" of the Garden, and her husband also participated in the walk, and were received with much enthusiasm by those who knew them. In the ring Mrs. Bowser was presented with a handsome bouquet, and Mr. Bowser with a suit of clothes, the gifts of members of the company. The usual circus performances were given.
The prizes went to the best (not fastest) walkers, so the activity in question again seems to have amounted to competitive promenading. It also seems not to have been an especially strenuous activity.
Likewise an untitled item in the [Hillsboro, Ohio] Highland Weekly News (January 15, 1880) indicates that a cake-walk had as much to do with poise and style as with physical exertion:
The colored Cake-Walk held at Music Hall last Thursday evening was a very successful affair, and was well attended. The cake was carried off by Mr. Lud McFarland and wife, who were decided to be the most graceful walkers.
'Cakewalk' as a sporting term
When boxing slang picked up and redirected the term cake-walk by the late 1890s, it seems to have done so with the idea that the original, literal cake-walk was not at all a difficult or physically punishing contest.
There is at least one scrap of evidence that horse racing may have picked up the term before boxing. From "Extra: In a Walk: Joe Courtney Had an Easy Victory at Guttenburg Today," in the [New York] Evening World (February 18, 1891):
Arizona [a racehorse] had a cake-walk. Mart Gibson [another racehorse] made a great bluff for nearly all the distance, when he quit very quickly and let Arizona walk in. Not Guilty [a third racehorse] was third.
But a few months later, in "Display of Fistic Science," in the Indianapolis [Indiana] Journal (May 22, 1891), the term appears in the context of a prize fight:
DISPLAY OF FISTIC SCIENCE: Many Rounds Fought by Jackson and Corbett Without Advantage to Either: The Much Advertised "Mill" Declared a Draw in the Sixty-First by the Referee After It Hid Resolved Itself Into a "Cake-Walk."
Here the implication is that, after slugging each other for 61 rounds, both Jackson and Corbett were so tired that all they could do was hold onto each other and walk (or perhaps stagger) slowly around the ring.
Conclusion
Newspaper article discussions of cakewalks in the 1870s suggest that the claim that a cake-walk was originally a dancing contest may be ill founded. It is certainly possible that cakewalks evolved over time into dance contests, but in its earliest manifestations a cakewalk appears to have been (as it name says) a contest between walkers—and one that focused on the appeal of the walkers stride, balance, posture, and grace of movement.