I have this:
On 21-22 April 1914, while leading three picket launches admist heavy enemy fire, McCloy was wounded but remained on his post, enabling cruisers to save American lives. For his gallant heroism, he was awarded his second Medal of Honor.
For heroism in leading 3 picket launches along Vera Cruz sea front, drawing Mexican fire and enabling cruisers to save our men on shore, 22 April 1914. Though wounded he gallantly remained at his post.
Is one of "at his post" or "on his post" wrong? Or are they both the same?