The very first can conceived by Coca-Cola was in 1936. This was a cone top can, but it was only produced as a sample. As far as we know, these cans were never test marketed or even filled. Shown here is the 16 ounce version. A 32 ounce can was also made. The only known examples of these cans are at the World of Coca-Cola in Atlanta, Georgia and the Schmidt Museum of Coca-Cola Memorabilia in Elizabethtown, Kentucky. These cans were never introduced to the public.
In 1955, Coke in cans was made available to the military in Japan. These steel cans weren't exactly the greatest for the product. A 1955 Business Week article stated, "You may be able to put Coke in a can but what comes out isn't Coca-Cola. It's a soft drink, non-toxic, but with a flavor that's as far removed from Coca-Cola as ginger ale is from India Ale."
It wasn't until September, 1959 that Coca-Cola first test marketed the can in Providence, Rhode Island and Brockton, Massachusetts. The general public saw the red can with a white diamond containing the words "Coca-Cola" in 1960.
So, the Coke can was first created in 1936, available to the military in 1955 and officially introduced to the general public in 1959.
Other can information:
The first aluminum can was introduced in 1957.
Coca-Cola introduced their aluminum can in 1960.
The pull-ring was invented in 1962.
Cans were first available from machines in 1965.
In 1974, the stay-on tab was invented.