Lee De Forest was born in Council Bluffs, Iowa, on August 26, 1873.
His father, Henry Swift DeForest, was a Congregational minister who hoped that his son would also become a minister. Henry accepted the position of President of Talladega College, a traditionally African American school, in Talladega, Alabama where Lee spent most of his youth. Ostracized by citizens of the white community who resented his father's efforts to educate blacks, Lee made his friends from among the black children of the town and, together with his brother and sister, spent a happy, though sternly disciplined, childhood in this rural community. His mother was Anna Robbins.
As a child Lee was fascinated with machinery and by the age of 13 he was an enthusiastic inventor of mechanical gadgets such as a miniature blast furnace and locomotive, and a working silverplating apparatus. But while Lee grew up in the deep South, his education was formal and upper class. Lee was sent to Mount Hermon boys school in Massachusetts. His life at school was hard, with chores as well as academics, plus work to supplement his scholarship. He was extremely concerned with getting recognition from his peers, an issue which lasted throughout his life. Alas, he only won acknowledgement as "homeliest boy in school". Despite this, he was confident. During school, Lee had tried to get money and fame by inventing things he might sell or enter in contests, but none were a great success.
Although his father had planned for him a career in the clergy, Lee insisted on science and, in 1893, enrolled at the Sheffield Scientific School of Yale University, one of the few institutions in the United States then offering a first-class scientific education. On one occasion he tapped into the electrical system at Yale one evening and completely blacked out the campus, leading to his suspension. However, he was eventually allowed to complete his studies. Frugal and hardworking, he supplemented his scholarship and the slim allowance provided by his parents by working at menial jobs during his college years, and, despite a not too distinguished undergraduate career, he went on to earn the Ph.D. in physics in 1899. By this time he had become interested in electricity, particularly the study of electromagnetic wave propagation, then being pioneered chiefly by the German Heinrich Rudolf Hertz and the Italian Guglielmo Marconi. Lee's doctoral dissertation on the "Reflection of Hertzian Waves from the Ends of Parallel Wires" was possibly the first doctoral thesis in the United States on the subject that was later to become known as radio.
His first job was with the Western Electric Company in Chicago, where, beginning in the dynamo department, he worked his way up to the telephone section and then to the experimental laboratory. While working after-hours on his own, he developed an electrolytic detector of Hertzian waves. The device was modestly successful, as was an alternating-current transmitter that he designed.
Lee was a poor businessman and a poorer judge of men. He was defrauded twice by his own business partners. In 1902 Lee joined a Wall Street promoter named Abraham White and formed the "De Forest Wireless Telegraph Company". Among their early customers were the War Department and the Navy. In order to dramatise the potential of this new medium of communication, he began, as early as 1902, to give public demonstrations of wireless telegraphy for businessmen, the press, and the military. Under the guidance of White, a public offering of stock was made, public demonstrations were held, and radio equipment was sold. But characteristic of his entire career, the hyperbole surrounding the company was greater than its actual value, and while Lee continued to invent, he was apparently unaware that White was engaging in less than ethical business practices. By 1906 his first company was insolvent, and he had been squeezed out of its operation.
That same year (1906) he invented of the Audion tube. At that time, he was a member of the faculty at the Armour Institute of Technology, now part of the Illinois Institute of Technology. He filed a patent for a two-electrode device for detecting electromagnetic waves, a variant of the Fleming valve invented two years earlier. His Audion tube, a three-electrode device (plate, cathode, control grid), was a vacuum tube which allowed for amplification for radio reception. Although he invented it he didn't really grasp the workings of it and it wasn't until 1912 when Edwin Armstrong made exhaustive measurements to find out how the Audion tube worked, and then devised the regenerative, or feedback (patented in 1914), circuit that the Audion tube came to the fore.
Lee moved to San Francisco in 1910. Working for the Federal Telegraph Company he assisted in developing the first global radio communications system in 1912.
The United States District Attorney sued Lee in 1913 for fraud on behalf of his companys shareholders, stating that his claim of regeneration was an "absurd" promise (he was later acquitted). Nearly bankrupt with legal bills, Lee sold his triode vacuum-tube patent to AT&T and the Bell System in 1913 for the bargain price of $50,000.
In 1916 Lee filed a patent that became the cause of a contentious lawsuit with the prolific inventor Edwin Armstrong, whose patent for the regenerative circuit had been issued in 1914. The lawsuit lasted twelve years, winding its way through the appeals process and ending up at the Supreme Court. The Court ruled in favor of Lee, although the view of most historians is that the judgement was incorrect!
In 1916 Lee, from his own,experimental, news radio station, 2XG, broadcast the first radio advertisement (for his own products) and also the first presidential election report by radio, in November 1916, for Charles Evans Hughes and Woodrow Wilson. A few months later, Lee moved his tube transmitter to High Bridge, New York. He had a license from the Department of Commerce for an experimental radio station, but, had to cease all broadcasting when the U.S. entered World War 1 in April 1917. Lee went on to lead the first radio broadcasts of music, which featured opera star Enrico Caruso, and many other events, but he received little backing for his endevours.
In 1919, Lee filed the first patent on his sound-on-film process, which improved on the work of Finnish inventor Eric Tigerstedt and the German partnership Tri-Ergon, and called it the "De Forest Phonofilm process". Phonofilm recorded sound directly onto film as parallel lines of variable shades of gray, and later became known as a "variable density" system as opposed to "variable area" systems such as RCA Photophone. These lines photographically recorded electrical waveforms from a microphone, which were translated back into sound waves when the movie was projected. This system, which synchronised sound directly onto film, was used to record stage performances (such as in vaudeville), speeches, and musical acts. In November 1922, Lee established his De Forest Phonofilm Company in New York City, but none of the Hollywood movie studios expressed any interest in his invention.
Lee premiered 18 short films made in Phonofilm in April 1923 at the Rivoli Theater in New York City. He was forced to show his films in independent theatres because Hollywood movie studios controlled all major theater chains. Lee chose to film primarily vaudeville acts, not features, limiting the appeal of his process. Max Fleischer and Dave Fleischer used the Phonofilm process for their Song Car-Tune series of cartoons starting in May 1924. The Phonofilm Company filed for bankruptcy in September 1926, just after Hollywood introduced a new method for sound film, the sound-on-disc process developed by Warner Brothers as Vitaphone, with the John Barrymore film Don Juan, released 6 August 1926.
Lee was also a prolific writer. At the beginning of his inventing career, he was a contributor to scientific journals and popular electronics periodicals. He wrote a self published autobiography, "Father of Radio", in 1950. He kept a daily journal, he wrote thousands of business and personal letters, several film scripts, and many poems.
During his life Lee married 4 times:
In his later years Lee lived in Hollywood and worked on a variety of non-radio technical devices. He continued to promote his legacy as the "Father of Radio", but his most important non-technical contributions to radio, his publicised pre-1920 broadcasts were far in the past. He became increasingly paranoid, believing that his failure to achieve recognition was because of his "enemies". He died on June 30 1961 at the age of 87, in Hollywood and was interred in San Fernando Mission Cemetery in Los Angeles, California.
Some sites claim "An important annual medal awarded to engineers by the Institute of Electrical and Electronic Engineers is named the Lee De Forest Medal." I can find no mention of such a medal ever being issued on the Institute of Electrical and Electronic Engineers website.