The men who filled the ranks of the newly formed Irish Brigade were from diverse walks of life. Many were canal workers, diggers, railway track layers, building labourers and hod carriers, whilst others were cabmen, porters, streetcar drivers, waiters, and barkeeps. Others were lawyers, college professors, school teachers, newspaper men, public officials, students, merchants and businessmen. Others were veterans of armies from around the world, seeing active service in various wars and campaigns. Men had previously served in the Hungarian Hussars; in Syria; in the British army in India and the Crimea; in the Papal Brigades serving the Pope in 1860 and 1861. It is easy to determine therefore that the experience previously gained by the men in conflicts would serve the Brigade well in future campaigns.
As the 69th New York State Volunteers were the first regiment of the Irish Brigade to reach their quota of men, they were designated the 1st Regiment of the Irish Brigade which can be seen clearly on the regimental flag. On 18th November 1861, a flag ceremony was held on Madison Avenue to present the regiment with the national Stars and Stripes, and the regimental colour, which had been made by Tiffany and Company.
Motto: Gentle When Stroked; Fierce when Provoked
By the end of August 1861, volunteers were needed to form a new 69th New York, a volunteer regiment. The old 69th New York State Militia remained as a militia unit during, and after the Civil War. Many of the old 69th wanted to see the 'job done' and see the Rebels beaten, so many joined the 69th New York State Volunteer regiment. According to Joseph Bilby, several hundred members of the 69th New York State Militia joined the new 69th New York State Volunteers, commanded by Colonel Robert Nugent; the writer Paul Jones believed the figure to be over five hundred.
Most of the 69th New York regiment was made up of recruits from New York City, but Company F came from Brooklyn, and most of Company K came from Buffalo, and Company D came all the way from Chicago Illinois. Meagher was offered command of the 69th New York State Volunteers but he declined. He had other, larger plans. He wished to form a brigade, a brigade of elite Irish American soldiers. This idea was a very plausible proposition. In the twenty years preceding the American Civil War, more than two million Irish emigrated to America. By 1860, forty percent of all immigrants into the United States were of Irish birth, with New York State boasting half a million of those, living in the main areas of Manhattan and Brooklyn, but with also large concentrations in Buffalo, Rochester, Albany and Syracuse. There was definitely an available population to fill the ranks of an all Irish, ethnic brigade within the Federal Army, and Meagher had the vision to make this proposition into a reality.