Assuming it is a common AVR-based board, and the serial port still appeared, I'm guessing it's a clone Uno/Nano, or official Nano? My guess is it's a clone nano - am I right?
(If the serial port doesn't appear, I would guess official Uno/Mega or higher end clone with a 16u2)
If you're curious about why:
An official Uno (or Mega) abused in that way will lose the USB serial port, and usually the pin13 LED will end up stuck on (from the opamp used to buffer it blowing as well). A clone Uno (or Mega) will rarely lose the serial port - the CH340G USB-serial chip the clones use is tough as nails (also cheap as dirt - you can't reprogram it to act as a keyboard/mouse with unojoy, or similar - but hardly anyone does that anyway; a Leo/Micro is a better choice for that as you don't need to fiddle with the 16u2 firmware since it has native USB) - but has the same opamp buffer scheme for the pin13 LED and power switching circuit, so pin13 will get stuck on. Those two components are the most "fragile" parts on the board, both very easy to trash by abusing the power rails, and applying voltages higher than 5v to an I/O pin will do that, because it will get onto the power rails through the protection diodes. Almost all microcontrollers have internal diodes on the I/O pins - these prevent the voltage on a pin from going higher than Vcc or lower than ground, serving to protect from static discharge. These are usually rated for 1mA max - this actually allows you to connect the pins to higher voltages as long as there's a resistor between that voltage and the pin that limits the maximum current (and injecting such a small current doesn't throw off the voltage on the power rails enough to damage other components either).
In any event, with clone Uno's at like $5, and nano/pro mini's under $3, at least it wasn't an expensive mistake. I buy cheap boards and modules (particularly serial adapters and programmers) in 3 or more at a time, and always recommend others to do the same, especially if you're new to electronics and hence at higher risk of damaging them. For me, it's not because I trash them that often (IIRC I have only trashed a few boards in the past 5 years by electronic abuse - more have been lost to simple mechanical damage), but I always end up wanting to either make permanent setups with them, or just plain lose them. I have so much electronic crap, and am so disorganized, stuff goes missing all the time.