1897 April 12 — Morning. F. L. Bullard, engineer on the Fast Mail train on the Chicago, Burlington, and Quincy Railroad, says he caught sight of an airship moving parallel with the train shortly after his Engine 950 left downtown Chicago. The train is moving at 70 mph, and by the time it reaches Lisle, Illinois, the object is far ahead. Bullard estimates it is moving at 100–150 mph.

1897 April 12 — 8:00 p.m. During a rainstorm in Lincoln, Illinois, more than 50 people stand on Pulaski Street to watch a light moving to the northeast. John Fitzgerald sees a V-shaped object with a bright searchlight moving rapidly toward Lincoln. It changes course, the light changes from white to green, and the object disappears behind clouds. 

1953 April 12 — 4:10 p.m. Ten round, flat, metallic objects changing formation are observed traveling at a high rate of speed at an estimated altitude of 7,500 feet over Sweetwater, Nevada. No trail, sound, or exhaust are noted. The objects pass under the right nacelle of the observers’ C-47 aircraft, which is en-route to Stead AFB [now Reno Stead Airport]. The co-pilot takes control of the aircraft and turns to the right in a tight 300° turn for a better view. The objects are then picked up unassisted by two more members of the crew. The objects are seen in a right turn of a greater radius than that of the C-47 and at a lower altitude. They are observed for approximately 120° of their turn and disappear on a heading of 300°. Observers are unable to estimate the speed of the objects because of the distance and the large turn radius.

1961 April 12 — Soviet cosmonaut Yuri Gagarin becomes the first human to go into outer space when his Vostok spacecraft completes an orbit of the earth.

1969 April 12 — During a Fouga Magister aircraft training mission at Pori Airport, Finland, a Finnish Defence Forces flight controller tells pilot-in-training Tarmo Tukeva to investigate seven air balloons that are floating at approximately 5,000–9,800 feet above the airport. Tukeva reports that the objects are ball or disc-shaped but cannot determine how far away they are. Tukeva sees the objects accelerate away from him “at great speed.” Indeterminate radar images are also later reported 125 miles away in Vaasa. A second pilot-in-training, Jouko Kuronen, overhears the radio communications between the flight controller and Tukeva and sees the UFOs as well. According to the Finnish Armed Forces magazine Ruotuväki, the reports are similar to other cases occurring over bodies of water during ongoing military exercises and may have been due to “transnational spy planes or aircraft.” https://en.wikipedia.org/wiki/Finnish_Air_Force_sighting ; https://www.ufocasebook.com/2013/finland1969.html

1979 April 12 — Early evening. A family is driving home from the grocery store at Brockton, Massachusetts. They see a piano-shaped object with lights all over it. A spotlight is beaming down, and there is one red light on top. They lose sight of the object, but suddenly all four car windows go down and back up; then they go down halfway and back up. The same thing happens when they stop at a red light. They see the object again, which is now following them. They park near their house, and the UFO hovers across the street. The man shuts off the engine and the windows act up again as the UFO moves directly overhead. The father and son get out of the car, and the UFO shoots a beam down at each of them in turn. It then moves down the street and away.

1988 April 12 — Coral Lorenzen, founder of APRO, dies in Tucson, Arizona. CUFOS had been attempting to purchase the APRO archives, but is thwarted by someone who convinces Coral’s son, Larry Lorenzen, that this is a bad move and that the APRO board should reconsider. He wants the archive to stay in Arizona. Tina Choate and Brian Myers, with their dubious International Center for UFO Research, convince the APRO board that they are the most logical recipients. In 1989, the board gives them the archives free of charge. Former APRO board member Robert Dean later realizes Choate and Myers are scam artists. They immediately bar anyone from using the files and move them to a garage at an undisclosed location in Scottsdale or Sedona, Arizona. It is not known if the paper archives still exist, although fortunately APRO case files prior to 1957 have been preserved digitally. In 2010–2012, Choate and Myers are involved in a fraudulent scheme to acquire and illegally sell a valuable collection of fossils. http://www.ignaciodarnaude.com/ufologia/Lorenzen,Coral,Obituary%201987,J.A.Harder,FSR88V33N3.pdf ; http://ufoevidence.org/documents/doc1145.htm ; https://www.courthousenews.com/collector-sues-over-25m-in-fossils/ 

1990 April 12–13 — Night. Two witnesses see a bright red light hovering above Little Sabine Island off Pensacola Beach, Florida. It stays there for several minutes before blinking out. It reappears the next night to the west of Gulf Breeze.