Cool thread. I didn't realize how long my post would be - you were warned...
On the Irish side (my mother): Left Ireland in the mid 1800s to escape the potato famine (thanks to the British occupation, Ireland was exporting food at this time) and poverty.
My grandfather grew up without his parents - he and his siblings were raised by his dysfunctional aunts. He joined the Army during WWII but never fought in combat because he was such a good instructor that the men he trained had much lower casualty rates and the Army decided to keep him training troops rather than fighting. After leaving the Army, he tried to be a teacher in many school districts but was never able to hold a job long because he was a bit of a crazy right-wing nut and prone to anger. One day when I was very young, a tax collector from the IRS came to see him (apparently he hadn't paid his taxes for years) at his house with my grandmother. My grandfather brought the man in, sat him down at the kitchen table, went into the other room to get his M1, and shot the guy at point-blank range. He did about 20 years in Attica in upstate NY for that. He got out a few years ago and died last year.
My mom had to move around a lot because my grandfather couldn't keep a job in one place for long. Eventually she went to college during the Vietnam war where she met my Vietnamese dad (more below) and helped teach him English through a refugee resettlement program. She dropped out of college, got a blue collar job as a machinist, got married, worked part time for the National Organization of Women after she had me, then divorced, moved, and started working as a machinist again before quitting. Now she has two part-time jobs working at a tourist agency in Rochester, NY.
On the Vietnamese side (my father): my grandfather's parents died when he was young and raised by relatives who were fisherman. When he was like 9 or 10, he did something "wrong" and he was literally thrown off the boat. He swam to shore and was on his own since then. By the time he became an adult, he managed to acquire a storefront in his hometown Nha Trang (a beach town on the coast of S. Vietnam) which owned for six or seven decades until his death last year. He was briefly involved in nationalist resistance against the French in the 1930s - apparently he and some of his friends acquired a handgun and were thinking of knocking off a local official in the colonial administration. Word got around and they got busted before anything happened. They were paraded through the streets in chains and my grandfather never got involved in politics again, although some of his comrades eventually joined the Vietnamese Communist Party and kept him out of trouble after they took power in 1975. My grandfather constantly attacked and criticized the government for corruption and ineptitude but the local party officials protected him.
He married a young beautiful woman, my grandmother, whom he was madly in love with but who did not love him back and married because of pressure from her family and for economic reasons. My grandfather felt this lack of love on her part and took it out on her and their many children, including my father. Altogether I think they had 8 or 9 kids, 3 of whom committed suicide in the late teens early 20s, and the rest of whom live in the U.S. today.
My father fled the South Vietnamese draft and came to the U.S. in 1970 or '71. He was not political until he got here - he knew nothing about the war or its causes until he got exposed to the anti-war movement here. Eventually he became a revolutionary (Stalinist to be exact) but did not join a Marxist organization. He got a degree in business from the University of Buffalo because that's what his father wanted (he's always had an interest in photography). He worked in various factories during and after he finished school. Eventually he got a job as a medicaid auditor for the State of NY which he has been doing for 20-30 years. He met my mom through the refugee resettlement program, fell in love, married, fathered me and my little bro, divorced, and recently re-married.
I wish I knew more about the rest of my family (grandparents, great grandparents, and above) like some of the people in this thread, but I have a feeling that their histories were just as if not more complicated than what I just outlined above.