What is recorded is his role in the document preparation.

The terms Grant offered were already largely settled before the meeting — Grant had communicated their general outline to Lee in previous correspondence, and Lee had indicated his acceptance before arriving at McLean’s house.

The meeting confirmed and specified the terms rather than negotiating them from scratch.

Once the content was agreed, Parker — as military secretary — prepared the formal written copies that would constitute the official record of the surrender.

The documents Parker prepared that afternoon still exist.