Things have often been hyped as “the best/greatest thing” since fire or the wheel. “The greatest thing since radio” was a popular saying in the 1930s and 1940s.
An advertisement for Kleen Maid Sliced Bread by the Chillicothe (MO) Baking Company, published on August 10, 1928, said, “She’ll (your mother—ed.) think it’s the greatest thing ever.” Broadway columnist Dorothy Kilgallen (1913-1965) wrote on March 10, 1951:
“My own sister has been to Far Rockaway, the Bronx, Upper Montclair and Montauk Point to catch the picture (King Solomon’s Mines—ed.). ‘He is the greatest thing since sliced bread,’ she says of Mr. (Stewart—ed.) Granger.”
American entertainer Red Skelton (1913-1997) said that television was “the greatest thing since sliced bread” in December 1951 and January 1952.
“What was the best/greatest thing before sliced bread?” is a jocular question that has been popular since the 1990s.
Wiktionary: greatest thing since sliced bread
greatest thing since sliced bread
1. (idiomatic) A relatively recent invention likely to significantly improve people’s lives.
Wikipedia: Sliced bread
Sliced bread is a loaf of bread that has been sliced with a machine and packaged for convenience. It was first sold in 1928, advertised as “the greatest forward step in the baking industry since bread was wrapped”. This led to the popular phrase, “greatest thing since sliced bread”.
Otto Frederick Rohwedder of Davenport, Iowa, United States, invented the first loaf-at-a-time bread-slicing machine. A prototype he built in 1912 was destroyed in a fire and it was not until 1928 that Rohwedder had a fully working machine ready. The first commercial use of the machine was by the Chillicothe Baking Company of Chillicothe, Missouri, which produced their first slices on July 7, 1928. Their product, “Kleen Maid Sliced Bread”, proved a success. Battle Creek, Michigan, has a competing claim as the first city to sell bread sliced by Rohwedder’s machine; however, historians have produced no documentation backing up Battle Creek’s claim. The bread was advertised as “the greatest forward step in the baking industry since bread was wrapped.”
10 August 1928, The Constitution-Tribune (Chillicothe, MO), pg. 4, col. 6 ad:
Kleen Maid Sliced Bread
that she buys down at the corner store. Y’ oughto tell your mother about it. She’ll think it’s the greatest thing ever.
Chillicothe Baking Co.
23 February 1940, The Bee (Danville, VA), pg. 3, col. 5 ad:
“Greatest convenience since sliced bread.”
Southern Twin-Pack Bread
29 March 1950, The Constitution-Tribune (Chillicothe, MO), pg. 1, col. 4:
First Loaf of Sliced Bread
Was Produced in Chillicothe
One of the greatest steps taken in the baking business was started right here in Chillicothe, says H. J. Kolbohn, operator of the Kolbohn Bakery.
That step was the marketing of the first commercially-sliced bread.
M. F. Bench, street commissioner here now and for many years a baker, was the one who introduced those first loaves of bread to the world—right here in Chillicothe.
“It caught on fast,” Bench recalls, “too fast. Neither the inventor nor myself ever made a cent out of the invention itself.”
The commercial slicing of bread caused two great advancements in the business, Bench said.
The first was that it improved the quality of bread. “A loaf of bread has to be good to be cut by the machine. And before the sliced bread came in, loaves didn’t have the quality they have now,” he explained. The second caused by the invention was that it made people buy more bread.
Perhaps folks found themselves eating more bread when they didn’t have to slice it. Maybe it was the habit many have of throwing the butt ends away, or waiting until last to eat them.
Bench began in business here in 1916 with a bakery at Clay and Martin streets. About 1931, or 1922, he built a plant on Elm street, now occupied by the Whistle-Vess company.
It was in that building, under the name “North Missouri Baking company,” that Bench put on the first sliced bread.
A friend, with whom he had done business before, invented the slicer. He patented the machine years before the first loaf of bread was put on the market. The man, O. F. Rohweddler (sic), had made dies with which to construct the machine. But before he could get to work, the building, housing the equipment burned.
By the time he was able to build another machine, some years had passed and the patent had expired. So when the machine was put in use here in 1928, the inventor was unprotected by patent, Bench says. The first sliced loaf of bread was produced in July of 1928.
The use of the machine spread much more quickly than Rohweddler or Bench had anticipated.
“It was no time at all,” Bench recalls, “when bakeries all over the nation were building their own machines. Other companies took right over.”
There was some skepticism here by some men who thought their “wives had little enough to do as it was without taking another job away from her.” But, according to Bench, the sliced bread was welcomed by the majority of most buyers.
And look at all the fingers which haven’t been cut because of it.
Old Fulton NY Post Cards
10 March 1951, Elmira (NY) Star-Gazette, “Broadway” by Dorothy Kilgallen, pg. 6, col. 6:
My own sister has been to Far Rockaway, the Bronx, Upper Montclair and Montauk Point to catch the picture (King Solomon’s Mines—ed.). “He is the greatest thing since sliced bread,” she says of Mr. (Stewart—ed.) Granger.
5 September 1951, Cumberland (MD) News, “Washington Whirl” by Austine, pg. 7, col. 2:
I really think they are the greatest thing since sliced bread, and if the time ever comes that men are on their way out, our first question will be..."Which way did they go?”
16 December 1951, The Courier-Journal (Louisville, KY), “Radio and Television Page” by Bill Ladd, sec. 5, pg. 19, col. 6:
“Red” Skelton, TV’s newest hot-shot, says, “Television is the greatest thing since sliced bread.”
6 January 1952, New York (NY) Herald Tribune, “Radio and Television” by John Crosby, sec. 4, pt. 1, pg. 1, col. 3:
“Don’t worry about television,” Red Skelton advised us in a recent interview. “It’s the greatest thing since sliced bread.”
OCLC WorldCat record
The greatest thing since sliced bread, a novel.
Author: Don Robertson
Publisher: New York, Putnam 
Edition/Format: Print book : Fiction : English
The great gas-tank explosion in Cleveland in 1944 is the crisis of this novel about a 9-year-old boy and his little sister who set out to walk to the end of the world.
OCLC WorldCat record
De Komeet : is hij een ‘little shit’ of ‘the best thing since sliced bread’? : Kasparov en de Londense wandelgangen: een portret
Author: Ally van der Pauw
Edition/Format: Article : Dutch
Publication: HP : Haagse Post, No. 35 (35 aug.1986), p. 12-15,
OCLC WorldCat record
The greatest thing since sliced bread is unsliced bread
Author: Paul Gillie; James F Holly; Welsh Hill Press & Forge,
Publisher: Hope Camp, Pennsylvania ; Shelton, Washington : Welsh Hill Press & Forge, 1994. ©1992
Series: Nostalgia papers, no. 4.
Edition/Format: Print book : English