George M. Cohan (July 3, 1878 Providence, Rhode Island- November 18, 1942 New York City) is considered by most scholars of theatre and vaudeville to be the most important figure in the history of musical theater. He was not particularly talented in the classic sense– his dancing was more hoofing and his singing voice had trouble reaching notes and ended up speaking the lines much of the time. Nor was he a great technical musician. But Cohan grew up performing in vaudeville and was already a veteran by age 8. He quickly emerged as a juvenile star on his own, at first because of his prowess at playing the violin. His mother and father were vaudevillians and with his sister at age 11 he formed a well-known vaudeville act, The Four Cohans which worked all the major vaudeville venues of the time including Tony Pastor’s. It is at that time that he began using his trademark encore comment on stage: “My mother thanks you, my father thanks you, my sister thanks you and I thank you.”
While growing up he got a good handle on what worked in a show and what didn’t and in his early twenties and looking quite boyish yet he began to put together his own Broadway shows as writer of words AND music (very unusual for the time), 
performer and dancer. His shows were produced and directed by him starring himself and he created more than 50 of them. At the start of his career he partnered with a sympathetic producer Sam H. Harris who knew how to calm perfectionist Cohan’s rages when things didn’t go exactly the way he had envisioned. The result was a series of over 50 smash hits beginning with Little Johnny Jones and including many other productions either created or financed As Cohan grew older his rages subsided and he became increasingly grateful for his successes, becoming known as a soft touch who would “lend” struggling actors, singers and comedians money that would never be repaid.
He saw it as his duty to help those less fortunate in his profession who had gotten caught without a net when vaudeville, ever a risky business, began to decline. Cohan himself had gotten very rich from royalties, including his popular sheet music and the renting out rather than selling of sketches which only he could use again and again. He was known for his boundless creative energy and for constantly writing something– stage directions, play books, hit songs– in his Fifth Avenue apartment in New York where he lived quite simply but elegantly. He took few vacations although he was often found in Atlantic City which was more of a different environment for his obsessive writing.
His songs not only became hits but sometimes became American institutions sung by soldiers and the general public and often imbued with that special kind of military patriotism that became his trademark. During World War I, his anthem Over There sung by vaudeville superstar Nora Bayes became THE rallying song of the Allied forces overseas and was also a tune that could be played as troops marched. I’m a Yankee Doodle Dandy also became classic Americana and was really a song about himself, “born on the 4th of July”. In the early years of the 20th century he was the boy wonder of Broadway featuring hit after hit in show after show. Little Johnny Jones and Little Nellie Kelley were shows that were particular smashes.
Songs such as Mary is a Grand Old Name was an enormously popular tune in its day and his salute to the Great White Way has become one of the great standards of 
musical comedy: Give My Regards to Broadway. Performing with his unique stiff legged dancing style and strutting back and forth across the stage, Cohan became a symbol of America and his enthusiasm for his country was contagious. On his deathbed during World War II, he was hoping to recover from his final illness so he could resume his duties as a Central Park area air raid warden! Cohan was personally proud of every American accomplishment and tried to celebrate it in song whether it was Lindbergh’s trans-atlantic flight or trying to find an anthem for the troops for World War II.
His star dimmed a bit in the teens when he refused to support the vaudeville entertainer revolt against the oppressive vaudeville owners’ monopoly on the business and he was condemned by the White Rats but there was no permanent animosity against him as his accomplishments were so numerous and so important that his name has become synonymous with Broadway. At the end, his wife and family were with him but also his closest friend Gene Buck, famous illustrator of Cohan’s and other’s sheet music and president of ASCAP, the American Society of Composers and Publishers. He was also a musical theater librettist and someone Cohan could trust and bounce ideas off of.
Not long before his death it was decided to make a film in Hollywood about his life. Cohan had never cared for Hollywood and his attempts at film-making there were met with constant frustration as he lacked the power and control he could exhibit on the Broadway stage. Nonetheless, James Cagney played the title role in Yankee Doodle Dandy and emulated Cohan’s singing style and eccentric dance stage prowling techniques. Cagney had wanted to do more musicals at Warner Brothers and had even been willing to work for less money and poorer production values in movies such as Grand National’s Something to Sing About (1937). His screen persona was always that of a wise guy or gangster but finally in this biographical film he was able to pour himself into a role that he deeply cared about. It was a tremendous hit and was also dear to Cohan who became famous to a whole new generation, received many awards and was suddenly in demand again at the age of 63 but he was sidelined with an intestinal condition, possibly colon cancer, which sapped his strength and eventually took his life in his New York City apartment looking over Central Park.