Seems like that one is in every history book, but aren’t there towns in Florida and New Mexico that are older?
They should count as founding settlements, now that they are in the US.
After all, even the original colonies were not considered connected, especially Delaware and New York (Dutch), so while we have absorbed them into our melting pot collective memory book, we shouldn’t forget the hispanic settlements that were on an equal footing.
What were those other settlements before 1620?
The first successful permanent settlement in the original 13 colonies was not in Massachusetts, but in Jamestown, Virginia, in 1607.
The Pilgrims in Mass. just had good advertising. 
St. Augustine Fl. was founded in 1565.
Just for starters, check out St. Augustine, FL (1565), and Sante Fe, NM (1607).
The first English settlement in the New World was at Roanoke in 1587 but the colonists disappeared and their fate is unknown (though there are theories).
–Cliffy
Peñitas, Texas in 1520.
Laredo, Texas in 1755.
The following site gives one list, but there are some problems with it.
It ignores Plymouth, MA (did they use some arbitrary size limit for inclusion on the list and Plymouth is too small?) and Jamestown, VA (which might be due to the size issue, similar to Plymouth, or may be due to the periodic destruction and relocation of Jamestown).
The following site discusses the previous list as well as providing information on other sites:
10 Oldest Cities in U.S. Reconsidered
Most of the California settlements by Spain did not occur until the eighteenth century, so they are out. Similarly, the French established very few cities, to begin with, and the ones that are now in the U.S. (e.g., Detroit, 1701) tended to be in the late seventeenth or early eighteenth centuries.
There are several cities located on the sites of earlier Indian villages or cities, but most of the larger ones went through a period of abandonment (usually due to depopulation by white disease) before the European villages/cities were established on the sites. My second link mentions Acoma, NM in that context. (Santa Fe was also occupied as a city/village site for several hundred years prior to the establishment of a European city by the Spaniards.)
A point of trivia: Plymouth isn’t a city; it’s still a town. That’s probably the reason it’s not on the list. I don’t know what requirements, if any, other states have by way of requiring communities of a certain minimum population to obtain a city charter, but Massachusetts isn’t one of them. Plymouth has about 46,000 people. Conversely, Maine, where I live, has several communities of under 5,000 that are cities. It’s up to the community to decide what sort of municipal government it wants.
The French settlement Charlesfort, now on MCRD, Parris Island, was settled in 1562, abondoned in 1563, although I am fairly sure St. Augustine still holds the record for earliest, so maybe they didn’t count that since it was short lived. The Spanish took over the area in 1570, building another fort, Fort San Felipe (II).
It’s often overlooked that many Europeans had spent a lot of time in America even before, and even vice versa. The Pilgrims survived because Squanto liked them and helped them - made easier because he spoke fine English, having lived in England for a number of years himself.
Along those lines, some claim that Childersburg, Alabama is the oldest:
After St. Augustine, I know that Micanopy, FL, a very small town outside Gainesville in Alachua County, considers itself the 2nd oldest town in the USA. The signpost as you drive through town certainly proclaims that. I looked for links on the net about this but found none. I went to school at the U. of Florida in Gainesville and distinctly remember this as I’m a bit of a history buff.
[url=http://www.iloveinns.com/bed_and_breakfasts/florida/shadyoak.htm]Almost. Maybe you shouldn’t have said what school you went to, what with the Crocodile, then this.
Screwed the code, but google “Micanopy, FL oldest”.
Another hit, coincidentally a UF site (the “Depatrment of Medicine” if you look at the title bar) repeats your claim of second oldest town in the US.
AAA South says this about it:
Somebody better stop the madness, Florida already has a bad rep for stupid people.
No one’s mentioned Annapolis, upon which site the French started a colony named Port Royal in 1605, two years before Jamestown. Later on, Port Royal was burned by the English who saw it as too much competition.
But if you want to count places that were later abandoned, then Cahokia in Illinois pretty much beats everywhere else. It dates back to somewhere around 700 AD.
The city vs town designation in Massachusetts is based on the type of municipal government only. There are no unincorporated areas of the commonwealth, and haven’t been since 1785 (the state incorporated all towns and cities that hadn’t done so themselves). Towns use a Board of Selectmen as their governing body, usually 3 to 5 people that take care of the town’s business. Cities have a mayor and a city council, the mayor handling day-to-day (and larger issues) stuff, the council doing their thing.
The only exception is the town of Weymouth (just north of Plymouth, in fact). They’re still called a town, but they have a mayor and council now. Go figure.