https://news.ycombinator.com/item?id=18427351
replyDesign and manufacturing is in the los angeles region aerospace industry cluster.
It's been a US company for the last 13 years.
https://rocketlabcorp.com/updates/rocket-lab-makes-its-defen...
RL incorporated in the USA to gain launch licenses.
replyThey've been an American company for over a decade at this point.