Update. It's just a coincidence that the newer open letter to Congress in the previous post, this thread (nd but approx March 3) …
https://ucs-documents.s3.us-east-1.amazonaws.com/science-network/Scientific-Society-Sign-On-Letter-signed-2-28-25.pdf
… and this older letter (nd but approx Feb 17) …
https://unitedsciencealliance.org/
… were both initially signed by 48 scientific societies. They're different letters, organized by different groups, and signed by (mostly) different societies.