My first example of chain migration was when I looked at the 1900 census and found Peter O'Malley 28, an Irish immigrant from County Mayo, his sister Winnie 24, and sister Mary, 20, living with their widowed aunt Margaret O'Malley Berry on Main Street in Somersworth, NH.
A Chicago cousin gave me his family's history. He said ... "my mother was the oldest and left Ireland at 16 to join her aunt, Onnie O'Malley who was married to an O'Malley and lived in Schenectady, NY. She lived there for several years before going to Chicago to visit the World's Fair. She stayed with her aunt Teresa Stanton Keane. In Chicago, she met and fell in love with her second cousin Thomas Lyons and they were married in 1939".
He then told me about his dad, Tom Lyons. "My dad was convinced at age 20 to leave Furmoyle with his brother Patrick by his uncle John McNamera who had done well in Chicago working for his uncle Tom Lyons, who started a hauling business with horses and wagons. Young Tom went to Chicago and got a job at "Lyons Bros" in 1926. Soon thereafter at the suggestion of his mother's uncle Patrick O'Malley, he worked for the General Electric Company building electric refrigerators. Then John McNamera went to the Fire Department and took Paddy Lyons with him. My dad got a job as a door man at the Drake Hotel on Michigan Boulevard and stayed there for many years until his cousin "Blond Tom" Lyons (son of one of the brothers who owned "Lyons Bros") was shot on the job at the Continental Bank on Lasalle Street in downtown Chicago. "Blond Tom" survived and went to work for the Fire Department, and my dad took his job as a guard at the bank and stayed there until he retired to Park Rapids, Minnesota".
So you see, it's all about family.