Here is just a small bit of info on Irish contributions to America after St. Brendan discovered it in the Sixth century!  St. Brendan would have hung around to greet the Vikings and Columbus, but  he had to return home by tea time.  More info on Irish-Americans can be found in "The Book of Irish-Americans"  404 pp. A great reference book!    Best regards,  Ed O'Dwyer.

Mathew Brady
Born to Irish immigrants, Brady is the best known 19th Century photographer.

George M. Cohan:  Grandson of Michael Keohane from County Cork.
Give My Regards To Broadway, Yankee Doodle Boy, and You're a Grand Old Flag are tunes that George M. Cohan left as part of the American Musical tradition.

Donald O'Connor:  Son of John Edward O'Connor of County Cork.
Starred with Gene Kelly in a series of films, including "Singing in the Rain."  Was the straight man in the "Francis The Talking Mule" series of film and played Buster Keaton in "The Buster Keaton Story.".

John Philip Holland
A submarine designer who finally convinced the U.S. Navy to use submarines in 1900.

Henry Ford:  Son of an Irish immigrant who married during the American Civil War.  Started the Ford Motor Company and the rest is history.

Willis O'Brien advanced the technique of "stop motion" photography for the film "The Dinosaur" in 1913.  He went on to use the technique for "King Kong" in 1933.

Justice William J. Brennan, Jr.   Son of  William Brennan of County Roscommon.
With the exception of William O. Douglas, has written more opinions than any other Supreme Court justice in U.S. history.

Dr. Thaddeus Cahill developed an electric typewriter in 1901.

John and Lionel Barrymore
In the 1920's the American stage belonged to the Barrymore's.  It was said that when Shakespeare wrote "Hamlet," he had John Barrymore in mind for the part..

Dion Boucicault, A Dubliner of Huguenot descent
In the latter part of the 19th century, this Irish-American wrote "Irish" plays for the American stage.  For more than half a century he was one of the most celebrated, versatile and successful men of the theater.  He is said to have originated the open-front shirt and was one of the first in New York to have a tiled bathroom.

Victor Hebert:  Born in Dublin, Ireland.
Well known for his light operas in the early 1900's.  He wrote the music for "Babes In Toyland." .

Eugene O'Neill:  
America's  most respected playwright who wrote "Long Day's Journey Into Night" and "The Iceman Cometh."

Nellie Bly (born Elizabeth Cochrane).
First made America conscious of the woman reporter by making a trip around the world in 72 days, 6 hours, and 11 minutes.  This created a great international stir in 1889.

Bat Masterson:  Son of Catherine McGurk from Northern Ireland.
Gunfighter, buffalo hunter, Indian fighter, and frontier lawman who assisted Wyat Earp in Dodge City. He went on to be a newspaperman inn his later years.

William F. Buckley, Jr., the host of "Firing Line". Buckley has long been a political spokesman for the conservative right in America.

Henry McCarty (changed his name to William Bonney known as "Billy The Kid." ) 
Made into a legend through the fiction of Hollywood, "The Kid" accepted a pardon, but is double-crossed in the process and escapes to be killed in the dark, unarmed at the age of twenty-one..

Marrion Morrison.  Who changed his name to John Wayne.
John Wayne has become a legend of American Film, but I best remember him in "The Quiet Man.".

 Buster Keaton..
The master of the "deadpan," Keaton became a star of silent film, including "The General" about the Great Locomotive Chase.

Bill Murray.
Star of Saturday Night Live and numerous films. (Not sure about Eddie Murphy)

John F. Sullivan who changed his name to "Fred Allen."
Anyone familiar with early 20th Century radio knows Allen's brand of comedy.  They don't make 'em like that anymore.  Get a tape of his "Allen's Alley" for a good laugh.

Eamon De Valera:
His American citizenship saved his life when the leaders of the Easter Rebellion in Ireland were executed by the British. That one event eventually led to the creation of the Republic of Ireland with Mr. De Valera as its first president.

"Wild Bill" Donovan.
Colonel of the "Fighting 69th" in World War I, he was awarded the Distinguished Service Cross, the Distinguished Service Medal, the Congressional Medal of Honor, a Purple Heart with two oak leaf clusters and the Croix de Guerre.  After the war he headed up the Office of Strategic Services (which evolved into the CIA.)

John Ford (born Sean Aloysius O'Feeney)
Ford directed "Stagecoach," "She Wore A Yellow Ribbon," Cheyenne Autumn," "The Informer," and many other great films that have become classics..

John Huston.
Director of classics such as "The Maltese Falcon," "The Treasure of the Sierra Madre," "The Red Badge of Courage," "The African Queen,", "Moby Dick," "The Man Who Would Be King," and many others.

Eddie Cochran.
"Summertime Blues" was his lock on stardom in 1950's Rock 'n Roll.  Along with another Irish-American, Bill Haley, they shaped the course of American music.