would
would you please tell me why the writer used would in this sentence and is it main verb or helping verb?
Early in his career Thomas Ala. Edison worked as a telegraph operator, which inspired some of his earliest inventions.[4] In 1876, he established his first laboratory facility in Menlo Park, New Jersey, where many of his early inventions would be developed. He WOULD later establish a botanic laboratory in Fort Myers, Florida in collaboration with businessmen Henry Fordand Harvey Firestone, and a laboratory in West Orange, New Jersey that featured the world's first film studio, the Black Maria.

Question

would
would you please tell me why the writer used would in this sentence and is it main verb or helping verb?
Early in his career Thomas Ala. Edison worked as a telegraph operator, which inspired some of his earliest inventions.[4] In 1876, he established his first laboratory facility in Menlo Park, New Jersey, where many of his early inventions would be developed. He WOULD later establish a botanic laboratory in Fort Myers, Florida in collaboration with businessmen Henry Fordand Harvey Firestone, and a laboratory in West Orange, New Jersey that featured the world's first film studio, the Black Maria.

Answer

What the others have said is correct. 'Would' goes with the verb 'establish'.

Answer

In 1876, Edison had not yet made his botanic laboratory.  He did it after 1876.  Because we are dealing with the year 1876, the author uses "would" to show that he will set up this laboratory later but hasn't done it as of that time.

Answer

Would in that sentence means that it was something he was still going to do.  Would here is used for the future.

Hope this helps.