Was anyone around back then? What was the general opinion of it?
If I am right the first altcoin was a Litecoin. Telling more it is the first fork of Bitcoin and maybe currency that one of the most developed and mined by users around the world. Litecoin show stable price results for a long time, this is good investment.
Namecoin NMC 18 April 2011; 1st fork of Bitcoin
Namecoin was the first fork of Bitcoin and still is one of the most innovative altcoins. It was first to implement merged mining and a decentralized DNS. Namecoin was also the first solution to Zookos Triangle, the long-standing problem of producing a naming system that is simultaneously secure, decentralized, and human-meaningful.