Downloading Historical Equities data

Hi,

I have a fairly heavy task and the LSEG help desk recommended that I put this question here in the dev community.

My team and I need to search and download data on equities (outstanding shares, price, dividend yield, etc.) traded on exchanges in 15-20 countries stemming back to the 1970's-present. My gut tells me that I should use the API, but given call limits, I'm wondering if there are more effective ways to go about it + how it might be done.

Many thanks!