iPhoto Library package deleted

Mac; OSXYosemite 10.10.13. Didn't realize this until my college son was home, asking where are all the pictures, he couldn't find on iPhoto. I showed him i saved them on a drive in different file folders, a few months ago...maybe in March 2015. When we opened those folders, the pictures looked lighter, and not all my pictures were there. He was looking for the iPhoto Library. Couldn't find it, anywhere. When I moved my pictures over, I also deleted everything I thought I didn't need..... then...I deleted the trash.... 😟