Date
What is the date on the coin? 1793? 1851? 1964? Normally the date serves to identify the time of mintage, but not always, as among early United States coins, for example, it was the practice of the Philadelphia Mint to keep dies on hand until they wore out. Although 19,570 silver dollars were coined in Philadelphia in the year 1804, these are believed to have been struck from dies dated 1803 and earlier. All 1794-dated half dimes were struck a year later in 1795, for although the dies had been prepared in 1794, the Mint didn't get around to coining half dimes from them until a leaf had turned on the calendar. However, for most coins the date represents the actual time of striking. All 1909 Indian cents were struck in 1909, and all 1951-S Franklin half dollars were struck in 1951.
I have always found it interesting to visualize events which occurred at the time of a coin's mintage. Although this drifts away from basic numismatics, I believe that it contributes to connoisseurship.
When I see a 1916 Standing Liberty quarter, or a Mercury dime of the first year of issue, I think of America prepared for the World War, up to date on the latest news from Europe, but hoping it would not be drawn into the conflict.
An 1854-S, 1857-S, or other early double eagle with an S mintmark instantly recalls the Gold Rush era and San Francisco, the commercial center of activity at the time.
1652-dated Pine Tree shillings of Massachusetts evoke feelings of colonial times, of a primitive way of life, of a time when America was largely unexplored.
No doubt a typical 1906-D $5 gold piece was coined from metal extracted from the Cripple Creek District, about 75 miles distant from the Denver Mint, an area once described as the richest gold camp on earth, a district which at one time had 50,000 inhabitants but which by the 1980s had fewer than a thousand (but which in the early 1990s began to prosper again - from legalized gambling).
The rare 1877 Indian cent - rare because of its low mintage - was produced in small quantities because there were financial hard times then, and the need for small change was lessened.
Zinc-coated steel cents of 1943, common and inexpensive today, are interesting as they represent a pivotal time in our nation's history, when copper went to war and had more important uses than making Lincoln pennies.
