Line breaks

It is my understanding that when there is a line break in a document, we are to transcribe it without the hyphen and on the line where the word begins.

I have been reviewing many of the Samuel Gompers letters and in many cases, they were transcribed as originally typed, with lines broken. 

I have edited them (I hope correctly!) to eliminate the hyphen and transcribe as one complete word, but have gone back and found the document has been reedited with the line break.

https://crowd.loc.gov/campaigns/afl/ilgwu-strike/mss511850155/mss511850155-735/  is an example.

Can you clarify, please?

Many thanks,

Doreen