Like all languages around the world, languages evolve over time. So are signed languages. The videos below from many decades ago show some evoluation of the language, ASL.
With the advent of available video camera, old ASL was able to be preserved. The most familiar film is "The Presevation of Sign Language" of 1913, signed by George Veditz.
Observe a few changes of ASL signs (a small part of the signs such as location, handshape, and/or orientation), such as WILL, ANNUAL (passive handshape), and YEAR-AND-YEAR (passive handshape). An interesting sign is COIN/MONEY.
Ernest Marshall (1910-1999) demonstrates some ASL signs "before" and "now" in the video above: LOVE, ?, JEALOUS, CHILDREN/KID, STRICT, a note about how many very short words such as IF are fingerspelled instead of signed, DEBATE, ASSOCIATION, WHO, WHAT, TELEPHONE (old kind), MOTHER/FATHER, PURPLE, LANGUAGE, ITALY, PROTESTANT/EPISCOPAL/LUTHERN, BIRTHDAY, BIRTH, GRADUATE, and WATER. Same for many other ASL words that have changed.
Few notes: CHILDREN is still used today as before. Just a new synonym KID was added. The old sign LANGUAGE emerged back today, replacing the initialized one.
Patti Durr shared some information about Ernest. He produced the "video letter" (above) to his friend Patrick Graybill a few months before he died at age 89 in 1999. Ernest was Deaf of Deaf family.
Here is another old video clip "The Lord's Prayer" signed by Mr. Matthew R. Mann at the age of 76 in 1937 at Tennessee School for the Deaf.
The channel holder of this video explains that according to a book, Mann was a student and then a teacher at Tennesse School for the Deaf from 1881 to 1934.
Related post: The Preservation of American Sign Language of 1913 by George Veditz, NAD.