Short answers, pulled from the story.
Tumblr was launched in February 2007 by software consultant David Karp and developer Marco Arment. The platform began development after a year of waiting for existing blogging services to introduce short-form blogs.
Yahoo! Inc. acquired Tumblr for $1.1 billion in cash on the 20th of May 2013. This transaction marked a significant turning point in the platform's history and led to user dissatisfaction.
Verizon Media announced the sale of Tumblr to Automattic on the 12th of August 2019 for less than $3 million. Matt Mullenweg stated that the site would operate as a complementary service to WordPress.com with no plans to reverse content policy decisions made during Verizon ownership.
On the 3rd of December 2018, Tumblr announced that all images and videos depicting sex acts would be banned from the service effective December 17. Exceptions included illustrations, political speech, medical events like childbirth or mastectomy, and gender reassignment surgery.
Tumblr launched and discontinued numerous features including Storyboard which shut down by April 2013 and Go90 video syndication which wound down at the end of July 2019. Group chats disappeared on the 22nd of September 2021 while Post+ was removed in January 2024 due to low usage.