How do I merge my photo's from my external hard drive into my iPhoto on my hard drive

Are any of these in an iPhoto Library? If the ones on the external are not, then just import them. It should report duplicates to you as it goes.

You do not give us enouth information

WHat version of iPhoto?

If these are just photos then import selecting not to import duplicates

If they are in two iPhoto libraries for the same version of iPhoto then use iPhoto Library Manager - http://www.fatcatsoftware.com/iplm/ - to merge the libraries eliminating duplicates

What do you have?

LN

And as photos or as an iPhoto library

Which ever it is you have to restore them to disk first and then use them - how you use them depends on what you have - which you still have not answered

I

f these are just photos then import selecting not to import duplicates

If they are in two iPhoto libraries for the same version of iPhoto then use iPhoto Library Manager - http://www.fatcatsoftware.com/iplm/ - to merge the libraries eliminating duplicates

What do you have?

LN

The photo's i have on my external are in my time machine backup

What is in the TM backup? An iPhoto library or just image files in folders?

OT

You will need to restore the library to your HD and merge your current library into the restored library with the paid version of iPhoto Library Manager.

Be sure to select Keep Both when asked which copy of the library you want to keep: