The idea came to him as he watched an employee taking the legs off a table to fit it into a customer's auto and realised that saving space meant saving money.
As both companies lowered prices, quality was threatened and the Ikea showroom provided a chance for customers to get a feel of the quality of the furniture before ordering them.
IKEA celebrates its Swedish heritage: the company's stores are painted blue and yellow like the Swedish flag and serve meatballs and other traditional Swedish food.
Kamprad formed the company's name from his own initials and the first letters of the family farm, Elmtaryd, and the parish where it's located, Agunnaryd.
Ingvar Kamprad was at a trade fair in Italy in the 1940s when he had an idea.
"He wanted to appear a man of the people, one of us", Stenebo wrote in a behind-the-scenes book, "The Truth About Ikea", released shortly after he left the company almost a decade ago.
Kamprad was known for his frugality, buying his clothes at thrift shops, driving an aging Volvo and bringing his lunch to work.More news: Smear tests save lives - make sure you attend yours
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"We have Småland in the blood, and we know what a krona is - even though it is not as much as it was when we bought candy and went to elementary school", he said, referring to the Swedish currency. In 2017, his fortune was estimated at $46 billion, according to the Swiss economic magazine Bilan.
He moved to Switzerland in the late 1970s to avoid paying Swedish taxes, which at the time were the highest in the world.
In a book in 1998, he admitted that he was a close friend of the Swedish fascist activist Per Engdahl, and a member of his New Swedish Movement between 1942 and 1945.
Sweden was neutral in World War II, and its Nazi party remained active after 1945.
Mr Kamprad said he stopped attending its meetings in 1948. But Kamprad said he stopped attending its meetings in 1948, later attributing the period to the "folly of youth", calling it "the greatest mistake of my life".
Kamprad died quietly in his sleep at his home in Sweden, the company announced.
In 2013, he was forced to hand over billions of dollars to his sons following a bitter family feud over intellectual property income that he kept for himself, according to a book on Ikea.
"He worked until the very end of his life, staying true to his own motto that most things remain to be done", the statement said.