The Wikipedia category “Irish emigrants to the United States (before 1923)” contains some 872 entries – that is, people notable enough to merit a Wikipedia article. This is really quite remarkable. Two of them have recently been brought to my attention, and deserve to be better known. From Wikipedia:

Patrick Sarsfield Gilmore (1829-1892) was an Irish-born American composer  and bandmaster who lived and worked in the United States after 1848. Whilst serving in the Union Army during the Civil War, Gilmore wrote the lyrics to the song “When Johnny Comes Marching Home.” This was published under the pseudonym Louis Lambert in September 1863…

In many ways Gilmore can be seen as the principal figure in 19th-century American music. He was a composer, and the “Famous 22nd Regiment March” from 1874 is just one example of his work. He held the first “Promenade Concert in America” in 1855, the forerunner to today’s Boston Pops. He set up “Gilmore’s Concert Garden”, which became Madison Square Garden. He was the Musical Director of the Nation in effect, leading the festivities for the 1876 Centennial celebrations in Philadelphia and the dedication of the Statue of Liberty in 1886.

Ron Good adds (having heard RTE’s P.S. Gilmore: Ireland’s First Superstar):

He made adjustments to the inclusion of instruments in bands (i.e. the addition of woodwinds) which resulted what we know today as concert bands. He also used anvils specially made in England which gave off sparks when struck with the hammers of dozens of faux blacksmiths.  Also used artillery pieces to add excitement.

Also from Wikipedia, we have notice of:

Thomas Francis Meagher (“Marr”; 1823-1867) was an Irish nationalist and leader of the Young Irelanders in the Rebellion of 1848. After being convicted of sedition, he was first sentenced to death, but received transportation for life to Van Diemen’s Land (now Tasmania) in Australia.

In 1852 he escaped and made his way to the United States, where he settled in New York City. He studied law, worked as a journalist, and traveled to present lectures on the Irish cause. He married for a second time in New York. At the beginning of the American Civil War, Meagher joined the U.S. Army and rose to the rank of brigadier general. He was most notable for recruiting and leading the Irish Brigade, and encouraging support among Irish immigrants for the Union. By his first marriage in Ireland, he had one surviving son; the two never met.

Following the Civil War, Meagher was appointed acting governor of the Montana Territory. In 1867, Meagher drowned in the swift-running Missouri River after falling from a steamboat at Fort Benton.

What a fascinating character.