Wikipedia:Selected anniversaries/September 27
This is a list of selected September 27 anniversaries that appear in the "On this day" section of the Main Page. To suggest a new item, in most cases, you can be bold and edit this page. Please read the selected anniversaries guidelines before making your edit. However, if your addition might be controversial or on a day that is or will soon be on the Main Page, please post your suggestion on the talk page instead.
Please note that the events listed on the Main Page are chosen based more on relative article quality and to maintain a mix of topics, not based solely on how important or significant their subjects are. Only four to five events are posted at a time and thus not everything that is "most important and significant" can be listed. In addition, an event is generally not posted this year if it is also the subject of the scheduled featured article or picture of the day.
To report an error when this appears on the Main Page, see Main Page errors. Please remember that this list defers to the supporting articles, so it is best to achieve consensus and make any necessary changes there first.
September 27: World Tourism Day
- 1540 – Pope Paul III issued the papal bull Regimini militantis, approving the formation of the Society of Jesus, a Christian religious order of the Roman Catholic Church, by St. Ignatius of Loyola.
- 1825 – Locomotion No. 1 hauled the first train on opening day of the Stockton and Darlington Railway, one of the first railways to use steam locomotives and carry passengers.
- 1905 – The physics journal Annalen der Physik published Albert Einstein's paper "Does the Inertia of a Body Depend Upon Its Energy Content?", introducing the equation E=mc².
- 1908 – The first production of the Ford Model T automobile (pictured) was built at the Piquette Plant in Detroit.
- 1983 – Software developer Richard Stallman announced plans for the Unix-like GNU operating system, the first free software developed by the GNU Project.