In the 1920s, Lyndall Fownes Urwick (1891- 1983) was an influential business consultant and thinker in the UK. He is recognized for integrating the ideas of earlier theorists into a comprehensive theory of administration. He wrote a book called The Elements of Business Administration, published in 1943.

Urwick worked in assisting the modernization of the business, bringing to bear his own thinking which had two main influences. One was the concept of scientific management, and the other, counterbalancing it in its emphasis on the humanity of management. Urwick's own prolific writings on management truly began in this period.

In 1925, George S. May, a flamboyant 25-year old, founds George S. May International Company and gets two clients after mailing out 50 letters. He serves his first client, the Chicago Flexible Shaft Company from a basement office in his home. May becomes infamous for commission-based marketing techniques. Perrin Stryker, wrote in Fortune: "Most consultants assume a primly professional attitude towards clients.

In the George S. May Company, the client is hotly pursued. Indeed, few companies in any industry have dared to sell their services so hard, so blatantly and so indiscriminately as does the George S. May Company."

Management theory was still in its infancy when James O. McKinsey (1889-1937) founded the firm that bears his name in 1926. He had left his academic career to build a firm that provided finance and budgeting services, but quickly gained a reputation for providing advice on organization and management issues.
Mac was determined to help senior management in American companies solve their most important business problems. In an era when "management engineers" were largely efficiency experts, Mac set out to enlarge the profession's scope by persuading clients that his young firm could not only help inefficient companies but also assist healthy companies in reorienting themselves to thrive in a turbulent business environment.

 

James O. McKinsey In 1927, An investigation started at Western Electric's Hawthorne factory in Chicago discovers that workers become more productive whether lighting is increased or decreased. It appears that the attention itself motivates them. In 1928, the age of the automobile has arrived. Andre Citroen writes an essay predicting that automobile transportation will fundamentally change the way civilized man lives his life.

 

In 1929, Edwin Booz Surveys hires its third employee, Jim Allen. The core of the firm that today is Booz Allen & Hamilton is formed.

General Motors has begun to regain market share from Ford in an epic battle, fought in Europe as much as in the United States. GM's European partner, Opel, makes major inroads into the market in Germany.

Andre Citroen In the 1930s,  depression creates more demand for consulting. Many big names got their start working to help companies navigate their way out of the Great Depression.

In 1933 McKinsey is joined by Marvin Bower, a Harvard Business School and Harvard Law School grad. He noticed that many companies needed management advice. In 1937 James O. McKinsey dies of pneumonia at the age of 48. Bower and Tom Kearney disagree over how to run the firm. Kearney keeps Chicago office in 1939 and calls it A. T. Kearney.

Bower wants a professional approach with a cultivated atmosphere: "My vision was to provide advice on managing to top executives and to do it with the professional standards of a leading law firm."

 

Bower sets rules including:

(1) put the interests of the client ahead of revenues,

(2) tell the truth and don't be afraid to challenge a client's opinion and

(3) only agree to perform work that is Marvin Bower necessary.

He insists on professional business language where jobs are "engagements" and the firm has a "practice." While Bower insists that consultants where hats and long socks (consultants still where the long socks). He shifts the focus of recruiting away from established experts towards graduate students who could learn to be good problem solvers and consultants.