33
/
AIzaSyB4mHJ5NPEv-XzF7P6NDYXjlkCWaeKw5bc
November 30, 2025
114811
10349
1
Public Timelines
FAQ

jan 1, 1929 - Overhead Projectors

Description:

First were used for the US military training, but then moved into the schools

Added to timeline:

6 Oct 2017
0
0
711

Date:

jan 1, 1929
Now
~ 96 years ago