“Eighter from Decatur, county seat of Wise” is the slang of craps shooters who want to roll an eight. It was sometimes given as “Ada from Decatur.” “Eighter” is first recorded in 1916 and “Ada” is first recorded in 1918. Some residents of Decatur, Texas claimed that there really was a woman named Ada, but more likely it was simply rhyming slang.
   
   
The Bingo Code
There is also a set of nicknames for rolls of the dice in craps, including:
Number Nickname
2 snake eyes
3 little britches
  acey-deucey
  trey
4=2+2 little Joe from Kokomo
  little Joe from Alamo
5 little Phoebe
  five in the South
  fever in the South
6 Jimmy Hix
  Captain Hicks
  sixty days
7 craps
  a natural
7=4+3 four and trey and take it away
7=5+2 five and two and you’re all through
8 Ada from Decatur
  eighter from Decatur; Ada from Decatur
9 Nina from Carolina
  Nina with her hair down
  Nina, Nina, ocean liner
10 Big Dick from Boston
12 box cars
   
The Legend of Ada 
As is often the case with historical “facts”, there are several versions of how the saying “Eighter From Decatur, County Seat of Wise” came about.  The two things that are certain is that it started out as “Ada From Decatur”, and that the story revolved around shooting dice.  The most credible version of the story comes from Dr. Ira E. Nash, who grew up in Decatur in the late 1800’s. 
 
As Dr. Nash later recalled, Will Cooper was a laborer and holder of odd jobs around town, who often worked in a barn that adjoined Dr. Nash’s boyhood home.  Will Cooper was described as a good worker with a love for both rolling dice and a local servant girl named Ada.  As his lucky point, Will would say “Ada From Decatur, County Seat of Wise” when rolling the dice, and this saying became popular in the local area.  The spread (and alteration) of Will Cooper’s lucky point began when a group of Home Guards and Army Regulars traveled by train to Virginia about 1900 to participate in a reenactment of the battle of Manassas. 
 
As luck would have it, Will Cooper had been hired as the cook for the Decatur participants, and during the long train ride, the troops entertained themselves with a number of pastimes, including playing dice.  This spread the phrase to a wider range of Texas Troops, and when they reached the huge tent city set up at Manassas to house reenactors from across the nation, the phrase spread, and went from being a general call for good luck to a plea for a Hard Eight.  After the “Battle” the troops returned to their home states, and the phrase “Eighter From Decatur, County Seat of Wise”, became know to entire generations of Americans who had no idea what an “Eighter” was, or where exactly to find Decatur or Wise County.
     
(Historical Dictionary of American Slang)
Ada from Decatur n. [pun on eighter + Decatur (Ala. or—as in 1984 ex.—Tex.) for rhyme] Craps. the point eight.
1918 Crowe Pat Crowe 87: You probably recall the thrilling adventures of Snake Eyes, Little Joe,...Ada from Decatur, and Box Cars.
1920 in Fitzgerald Stories I 212: Ada from Decatur rolled over the table.
[1939 Hart 135th Sq. 30: Eighter from Decatur, the County seat of Wise.]
1978 Hayakawa Lang. in Thought & Act. 174: In craps, the dice-thrower will call for “Little Ada from Decatur,” and if he rolls a seven before an eight, he attributes his failure to “the wrong kind of call.”
1984 Sample Racehoss 30: Ada!! frum Decatur, the county seat a’ Wise. Eight! 
 
19 November 1916, Washington Post, “Pay Day Joy in Mexico,” pg. ES5, col. 1:
There is a great snapping of fingers, and the men bending over the tables are heard to utter these mysterious cabalistic words: “Come on, Little Joe!” “Git him, seben!” “Baby needs a pair of shoes!”  “Eighter from Decatur!” “
       
25 October 1919, Belleville (IL) News-Democrat, pg. 8:
Patrolman Barbee responded and when quite a distance away he could hear the shouts of “little seven,” “Ada from Decatur,” etc. 
 
23 November 1919, Atlanta (GA) Constitution, “Two and Three” by Bugs Baer, pg. A2, col. 4:
Back to the office, where Citronella breaks out a pair of dice. All the girls separate their pennies from their chewing gum and aspirin tablets, while Edith and a few visiting mannikins from the Debris
feminine harness shop squeak for first roll at the dotted caramels. Simpie cops all the Darb. She has a gentleman friend who is a padroller and Simpie knows how to control the five. . . . The girls have their own labels for the points. Four is Little Josephine. Eight is Ada, from Decatur. Nine is Nellie with the Long Green stockings. Ten is Big Ben. Two aces are Aromatic Spirits of Ammonia. Eleven is the Prince of Wales and twelve is your own fault.
 
26 March 1920, Kingsport (TN) Times, “Sh-! Not a word now, but boys’ll be boys,” pg. 10, col. 6:
Ada, whose residence is to be Decatur, Ga., is popular, as is also a lass yclept Phoebe. The Richards, Senior and Junior, have become so familiar to the boys that they call them Big Dick and Little Dick, and there’s strange talk about sixty days on the rock pile, snake eyes, throwing your arm off, box cars, slow death, and so forth.
   
16 January 1921, Syracuse (NY) Herald, “The Jelly Bean” by F. Scott Fitzgerald, pg. 2, col. 6:
Ada from Decatur rolled over the table.
 
21 November 1927, Bridgeport (CT) Telegram, “The Fun Shop” by Maxson Foxhall Judell, pg. 4, col. 5:
De dice am clickin’ so fast you’d think you was in a telegraph office, and Nappy makes ebery point on de dice and some dat wasn’t on ‘em-Little Joe, Feber in de South, Five and a Half, Sixty Days, Two Months and a Half, Eighter From Decatur, Eight and Three Quarters, Three Boxcars and the Caboose-he -made ‘em so fast dat he had to change to asbestos dice when de others burned up!
 
3 October 1937, Washington Post, “On a Cold Trail” (Memphis Commerical-Appeal), pg. B8, col. 6:
Two is “Snake-eyes,” and four is “Little Joe.” Five is either “Fever” or “Phoebe,” and an eight is an “Eighter from Decatur.” A nine is “Nina from Palestina,” at least in some circles where the boys kneel and not precisely in devotion. A ten is “Big Dick from Dixie,” and a twelve is “Boxcars,” but three is just plain “Craps.”
   
18 July 1949, Dallas Morning News, section I, pg. 1:
Town Council Will Discuss
Approval of Famous Phrase
By FRANK X. TOLBERT
(...)
Cliff D. Cates, author of “The Pioneer History of Wise County,” supplied the historical background on how Decatur became famed among dicemen.
 
“Long years ago there was a Negro girl in Decatur named Ada,” said Cates. “She was a favorite of Negro cowboys at the Waggoner Ranch and other dark-skinned citizens of the county. These boys, started yelling, ‘Ada from Decatur, County Seat of Wise’ when they were trying to roll an eight.”
 
White-folks gamblers misunderstood and changed the phrase to “eighter” instead of “ada,” said Cates.
 
The Eighter from Decatur” cry was a local thing up until World War I.
 
Texas crapshooters in the army and navy spread the exlcamation all over the globe.
 
By 1918 “Eighter from Decatur, county seat of Wise” was being yelled in every accent from Afghanistan to Russian.

18 May 1955, Dallas Morning News, “Tolbert’s Texas” by Frank X. Tolbert, part 3, pg. 1:
The legend is that Negro cowboys on the Dan Waggoner ranch many years ago in honor of a popular Negro girl named Ada. They’d yell it: “Ada from Decatur, etc.” During World War I it was changed from Ada to Eighter and the cry spread throughout the world.
 
6 March 1956, Dallas Morning News, “Lady Curious About Crapshooters Cry” by Frank X. Tolbert, part 3, pg. 1:
And from Decatur Mayor Syl Hardwick, via Historian Cliff Cates, I have one story of how Decatur became a byword for crapshooters.
 
“Long ago, there was a good looking Negro girl named Ada,” said Cates. “Her last name has been forgotten. She was quite a belle among the Negro cowboys, who always called her Ada from Decatur.”
 
Ada was courted by a giant Negro, named Solomon, who worked on the Waggoner Ranch. Solomon couldn’t spell and he associated his girl friend’s name with the figure eight.
 
ONE NIGHT IN the 1890’s, Solomo was shooting craps in the bunkhouse. He was trying to roll eight and he yelled: “Eighter from Decatur, the county seat of Wise!” He got an eight.
 
That started a cry that was to be heard around the world. During World War I, Texas crapshooters made “Eighter from Decatur” known all over Europe. (...) DECATUR HAS had the Eighter signs less than 20 years. (...) As for Ada from Decatur, the belle of the Negro cowboys, no one knows what became of her.
 
One elderly Wise County Negro says:
 
Ada went to Fo’ts Wuth in 1910, and that’s the last we hear.”
 
19 May 1962, Dallas Morning News, “Religious Leaders Fight ‘Dice Signs’” by Frank X. Tolbert, section 4, pg. 1:
“HERE AT DECATUR Baptist College, we are praying and working with every fiber of our beings that the town of Decatur may some day be rid of those terrible, crap shooting signs,” said Dr. Otis Strickland, president of Decatur Baptist College.
 
The college president was referring to signs on the highway approaches to the capital of Wise County which have pictures of pairs of dice making the point of eight. These also proclaim: “This is the Home of the Famous Eighter from Decatur, the County Seat of Wise!”
 
These signs were first put up years ago by a Decatur civic club in acknowledgment of the fact that dice players all over the world, while trying to roll an eight, often chant: “Eighter from Decatur, the County Seat of Wise.”
(...)
DR. STRICKLAND TOLD a version of how the “Eighter from Decatur” cry started that I’d never heard before: “Two fellows were shooting dice in a box car in Fort Worth, and one of the gamesters was about to try and throw for the point of eight. At this juncture, they heard a woman singing. One gambler said: ‘Who is that singing?’ The other, the one with the dice, replied: ‘Oh, that’s just Old Ada from Decatur.’ While he was saying this he rolled his point.”
 
The late Calvin Dodson, a wealthy one-time mayor of Decatur, told another story. he said that the cry was first started by a Negro range cook for the Waggoner Ranch, which then had its palatial headquarters right in the town of Decatur.
 
The range cook was (1) very fond of shooting dice, and (2) had a girl friend named Ada. And the cowboy chef was frequently successful in making the point of eight while crying out: “Ada from Decatur.” Ada was later corrupted to “Eighter.” According to Mr. Dodson, Texas crapshooters in the army during World War I caused the chant to become popular all over the world.