I am looking for a children’s book from around 1980.

I do not recall the title or author, and the book may have been published before 1980.  Let’s say anywhere between 1970 and 1982 or so.  This was a favorite book of mine when I was a kid, and I used to take it out of my local branch of the St. Louis Public Library pretty regularly.

The one thing I DO remember were the fantastic illustrations.  It was done in black and white, and the drawings looked as though they may have been pen and ink, or etchings, and they were very realistic.

Thematically, I remember a couple things about the story:  A boy and his cat used to sit on a hill under their (or maybe the cat’s) favorite tree.  At night, the cat would go have adventures on his own with his cat friends.  Toward the end of the story, the cat died, and the boy and his mom decided to bury him atop the hill under the beloved tree.  Then the boy would go there to remember the cat.

Specifically, I recall one page in the book that illustrated night time, when the cat would go with his cat friends.  There is a house (presumably the cat’s) in the background, as though he has just been let out for the evening.  In the foreground, you see the cat joining up with many, many neighborhood cats as they set off to roam around–a virtual cat army.

Thank you, and I look forward to seeing what you all come up with.