Short answers, pulled from the story.
Friedrich Bayer and Johann Friedrich Weskott opened a partnership in 1863 within the German town of Barmen. They established a facility to produce dyes for the textile industry.
A new city named Leverkusen was founded there in 1930 to house the corporate headquarters. The company relocated to Wiesdorf near the village of Leverkusen after further expansion proved impossible in Elberfeld.
Arthur Eichengrün claimed he discovered the formulation that eliminated nausea and gastric pain while Felix Hoffmann is credited with inventing the name. Bayer launched acetylsalicylic acid under the trademarked name Aspirin in 1899.
The company paid RM 170 per person for the use of 150 female inmates. Almost half of IG Farben's workforce consisted of slave laborers or conscripts by that time.
Bayer merged with Monsanto in May 2016 for $62 billion making it the biggest acquisition by a German company to date. The deal closed on the 7th of June 2018 after regulatory approvals from both the European Union and the United States.