If you do git log --patch -- path/to/file, you will get the history of the file along with a diff of all the changes made to it with each commit, like this:
git log --patch -- path/to/file
If you're on Linux, Then install TIG as:
sudo apt-get install tig
and then,
tig path/to/file/
It'll show you all the commits and their respective changes
Talat Parwez