Lifelong Jew here, but I took some courses in Christianity in college, because before I got my school to accept an independent minor in Deaf Studies, and I went to Gallaudet for most of my Deaf studies courses, I planned a minor in Religious studies. Anyway, I believe that Anglican churches outside of the UK all trace the lineage of their bishops through a guy named Samuel Seabury. Prior to Seabury (possibly not the church in Canada, or other churches the are or were part of the British commonwealth), there were no bishops from any Anglican church in the Americas. Any time a deacon wanted to be ordained priest, the person had to travel to England to find a bishop for the ordination.
Anglicans/Church of England/Episcopal church/et al. believe in something called the Apostolic Succession, which means that every single ordained bishop can trace the laying of hands to the apostle Peter.
The US, as soon as it was the US really wanted its own bishop, and the need became more acute once it became the US, because the Church of England required, as part of the ordination, a loyalty oath to England. However, the Church of Scotland did not.
So the new citizen of the US, and priest of the US Protestant Episcopal church, Samuel Seabury, went to Scotland for ordination as a bishop, and returned to the US with the ability to create more bishops within the US.
Later, as the Episcopal church set up missions in other countries, and other churches with other names popped up, they still traced their apostolic succession through Seabury.