I hope this info is of help.

Journal of the executive proceedings of the Senate of the United States of America, 1848-1852
SATURDAY, March 17, 1849.
Washington, 16th March, 1849.
To the Senate of the United States:
I nominate William B. Scott, esq., of Louisiana, to be marshal of the United States for the eastern district of Louisiana.

Journal of the executive proceedings of the Senate of the United States of America, 1848-1852
THURSDAY, March 22, 1849.
To the Senate of the United States:
I have ascertained that in nominating Mr. Scott to the Senate as marshal of the United States for the eastern district of Louisiana, I committed a. mistake in naming him William B. Scott instead of William S. Scott, and he has consequently been confirmed and commissioned under wrong Christian name. For the purpose of correcting this mistake, I now nominate William S. Scott to be marshal of the United States for the eastern district of Louisiana.

Note: It’s recorded in the Louisiana Eastern District of the Marshal Office, that William S. Scott, was Marshal and not William B Scott.