Felicite, welcome to G2G.
You added a profile for James E Burnside (Burnside-757). There already was a profile for James: Burnside-658.
Go to the bottom of James (Burnside-757) page, (Matches and Merges),
click on [initiate a merge], on the new page enter ID 2: Burnside-658, you can COMPARE both profiles side by side to be sure they are a duplicate, then click on merge them to proceed to complete the merge.
If any other doubt come back to G2G.
Best of luck.