I'd switch to a more batch-oriented approach, rather than going one-by-one.
For example, scan a half-dozen or so images.
Don't edit anything on any of them, just scan them.
Select them.
Move them to an album named "1959".
This won't change their dates, but it will group them all in one album for later date-changing. Later on, when you can go into the "1959" album and change the dates, you'll only need to go to the top of that album, rather than going to the top of your entire Photos library.
Obviously, you'd first make an album named "1959", but after that, you should be able to move an entire set of selected images at once. See "Control-click" under "Add photos to an existing album" here:
In Photos on your Mac, create albums to organize your photos. Add, remove, and rearrange photos in an album.
support.apple.com
Another possibility might be adding the keyword "1959" to an entire set of selected photos. I'm not sure if this is available, so you'd have to look for it when you have multiple photos selected.
In Photos on your Mac, use the Info window to add titles, captions, locations, dates, and times, identify people in photos, and more.
support.apple.com
The reason for adding a keyword, as distinct from a date, is to operate on them using a Smart Album later.
Or maybe you can directly change the data of multiple photos. I don't know, because I don't use Photos. If it's available, it's likely under Control-click, if it's possible at all.
You may find other useful info in that Photos User Guide. I suggest reviewing its Table of Contents.
Since you mentioned a trackpad, a "control-click" is a two-finger tap on the trackpad, if it's configured that way in Trackpad preferences.