While at high school he enrolled in a correspondence course in electrical engineering and organized an amateur telegraph circuit linking the homes of fourteen of his friends.

The business struggled at first, but in the second year gained profitable contracts from the Stockyards and the Peavey Grand Opera House in Sioux City.

In 1903 McGraw organized the Interstate Supply Company in partnership with his father and four others, selling mill, railroad and electrical equipment.

In 1912 he bought the Lehmer Company, a mill supply and electrical equipment manufacturer which he had used as a model for his earlier enterprises.

The company shifted its focus from power supply to telephone service, and formed the nucleus of what became the Centel Corporation.

"[5] In 1959 McGraw named Al Bersted president of the McGraw-Edison Company, retaining the position of chairman of the executive committee.

[1] In 1938 McGraw bought 2,000 acres (810 ha) of land near his new plant in Elgin, Illinois and made it a protected wetland.

The Elgin plant converted more than 1,000 loaves of bread into toast each day as part of its toastmaster testing process.

[6] The Max McGraw Wildlife Foundation managed crop fields in northcentral Illinois, and allowed dove shooting on a few days each year.

The beautifully prepared book had photographs of natural scenes in the US by Ansel Adams and text by Nancy Newhall.

It supports various causes, including higher education related to science and the environment, and provides significant funding to the Max McGraw Wildlife Foundation.

[9] The mission of the Max McGraw Wildlife Foundation is "Secure the future of hunting, fishing and land management through programs of science, education, demonstration and communication".