Most financial data providers limit historical downloads to one ticker per API call. You can imagine that pulling multiple time series in the same JSON output is confusing and puts heavy loads on servers.
There is a Ruby wrapper of Intrinio's API on github, you can see it here, that will make it easier to get historical time series data.
This will pull Apple's price history:
curl "https://api.intrinio.com/prices?ticker=AAPL" -u "APIusername:APIpassword"
This will pull the current price dimensionally, for up to 150 stocks:
curl "https://api.intrinio.com/data_point?ticker=AAPL,MSFT,T,XOM&item=last_price" -u "APIusername:APIpassword"
You will, of course, need to exchange your own API keys in the curl, but using the github wrapper will make it easy. API username and password are free.