I accidentally unplugged my iphone from my computer before it finished importing, how do I force quit?

Howdy alexfromtexas,

Thanks for using the Apple Support Communities.

I'm not sure which application you were using to import the Photos from your iPhone, but if you follow the directions below you can force quit any app on your Mac.

1. Choose Force Quit from the Apple menu, or press Command-Option-Esc
   (this is similar to pressing Control-Alt-Delete on a PC).
2. Select the unresponsive app in the Force Quit window, then click Force Quit.

Force an app to close on your Mac - Apple Support

Have a good one,

Alex H.