Webster's 1828 dictionary's entry for "barge" defines it as a "vessel or boat of state" or a " flat-bottomed vessel of burthen, for loading and unloading ships."
Noah Webster, 1828 Webster's Dictionary, (The Editorium, 1828), "Barge," accessed January 20, 2023
B'ARGE, noun barj. [Barge, and bark or barque, a ship, are radically one word.]
1. A pleasure boat; a vessel or boat of state, furnished with elegant apartments, canopies and cushions, equipped with a band of rowers, and decorated with flags and streamers; used by officers and magistrates.
2. A flat-bottomed vessel of burthen, for loading and unloading ships.