The real Alice

First questions
Who wrote Alice in Wonderland, and when?
Lewis Carroll published Alice's Adventures in Wonderland in 1865, with John Tenniel's illustrations. Carroll was the pen name of Charles Lutwidge Dodgson, an Oxford mathematics lecturer. Its sequel, Through the Looking-Glass, and What Alice Found There, followed in 1871. Much of what people "remember" from Alice is actually from the sequel: Tweedledum and Tweedledee, the Jabberwocky, the White Queen. That is one of several conflations this site untangles.
Is Alice in Wonderland public domain?
Yes. Both Alice books and the original Tenniel illustrations are long out of copyright worldwide. That is why you can read the complete text free — Project Gutenberg hosts it — and why adaptations keep coming. What is NOT public domain: the 1951 Disney film's designs and songs and the 2010 Burton film's inventions. The distinction matters practically — Carroll's text is everyone's; Disney's blue dress is Disney's.
What is the story actually about?
A seven-year-old follows a waistcoated White Rabbit down a hole into a world running on dream-logic. There are size changes, a mad tea party, a croquet game with flamingo mallets, and a trial where the verdict precedes the evidence. Alice holds her own against all of it with literal-minded courage, until the pack of cards flies apart. Adult readings sit alongside the children's story: satire of Victorian manners, mathematics jokes, logic games. Carroll was a logician entertaining a real child named Alice Liddell, and he wrote both at once.