You get everything you see in the pics...the original mailing envelope, the Philadelphia souvenir view book along with the Sesquicentennial International Exposition Booklet.
The envelope as you can see is pretty beat up and has been used mainly for just storage.
The booklet at the bottom of the first picture...the front and back cover are there but they are both separated from the booklet. I'm assuming that last page is the back cover...could possibly be missing a page but it looks correct to me.
The souvenir view book is in great condition. No major flaws with it...just standard appropriate wear for age.
See pics for more details.