No as it is not in the list of 18 shootings, so the Washington Post is counting 1 as being 1 of the 18 whereas it is not on the list.
No Mr. Slartibartfast, you "should understand" which date is most relevant to the context of your original quote below (with my comments in brackets; N.B. even the 1789 date renders your claim false on its face). "The well regulated militia line [from the 1791 Second Amendment] was before the US Army was created [in 1775] to replace it." You should also butt out of matters that don't pertain to you and of which you have no knowledge. You should also have the humility to admit when you're wrong. OTOH, if you (and your ilk here) did that, there would be nothing to laugh at and mock. So please keep up the good work!
Fear not Mr. Slartibartfast, because help for TDS sufferers like you is as near as your smartphone "from the Real America where the majority rules." At http://www.hillarybeattrump.org/ Hillary Clinton won the election and all the news is inspirational. As an added benefit, the site is specifically designed to be navigated with only one hand! So why go anywhere else when you can thrill to reports like: Impassioned Clinton labels the NRA "America's leading domestic terrorist organization" New York Times slams Clinton for giving "yet another excellent press conference" President Clinton proudly calls America a "sanctuary nation"
FBI admits it didn’t investigate tip on alleged school shooter last month. https://nypost.com/2018/02/16/fbi-failed-to-investigate-tip-on-school-shooter-last-month/
I'm sorry, you are too small and I'm not autistic so I will only ever struggle to understand. You may be interested to know there is another famous Poindexter.