At some point I looked into it, and if the laws were what they are today, Disney wouldn't have been able to make Alice in Wonderland (1951) without paying Lewis Carroll's (d. 1898) estate until 1968. The Little Mermaid (1989) was safe though, since Hans Christian Andersen died in 1875 (so his copyright would have expired in 1950).
At some point I looked into it, and if the laws were what they are today, Disney wouldn't have been able to make Alice in Wonderland (1951) without paying Lewis Carroll's (d. 1898) estate until 1968. The Little Mermaid (1989) was safe though, since Hans Christian Andersen died in 1875 (so his copyright would have expired in 1950).