Trying to download photos from my iphone to my macbook - can only see a small portion

Hello - Recently I exceeded my storage capabilities on my iphone so in order to clear up space I am trying to download my photo library on my phone to my computer so I can free up some space on my iphone. The problem I am having is that I cannot see my entire photo library when I plug my phone into my macbook - I only see about 30 days worth of photos and I can't seem to access the other portion of my library.

Can someone please help me figure out how I can regain visibility to my entire photo library?

Thank you -

Lenny