Quandl has some dataset of altcoins but the history is small and unfortunately prices are not updated.
CoinMarketCap JSON API is great but I understand it provides the lastest update only.
I have found on Bitcoincharts a file named rippleUSD.csv.gz but I don't understand the structure.
A convertion of the unixtime with in MS Excel (i.e. =A1/(60*60*24)+"1/1/1970") returns the following dates and time but it is not clear if the last column is price because movements in a single minute interval are huge.
Looking at the Market Overiew API I haven't found relative informations about CSV file structure.
How to Get Cryptocurrency Prices using Python - Markets and Data
Sorry my status does not allow me to post more than 2 links
Do you know if there is website where it is possible to download historical price of big cap crypto currencies such as Dogecoin, Bitshares, DarkCoin and Ripple ?