One of the first Omega-class ships to come out of construction line after the Earth-Minbari War.
Before being transferred to B5 Sheridan commanded the Agamemnon for two years on deep range patrol.
After the Captain was captured by the Streib in 2259, Agamemnon's crew helped the station's command staff to rescue him.
The next time Sheridan and Agamemnon's paths crossed was in 2260 when Earth was trying to gain new technology from a Shadow vessel buried on Ganymede.
Sheridan and Delenn took the White Star to Earth space and managed to destroy the vessel
but were almost captured by Agamemnon (which at the time was patrolling in Earth space).
Fortunately the White Star managed to escape without having to open fire on Agamemnon or revealing Sheridan and Delenn's identity.
When the civil war on Earth broke out in 2261, Agamemnon was among the ships that defected to the resistance.
During the last battle against Clark Sheridan commanded his fleet from his old ship and when the president turned Earth's planetary defense systems against the planet itself,
Agamemnon was among the ships that were close enough to help.
When the ship's weapons systems were damaged, Sheridan gave the order to ram into the last defense platform still threatening Earth.
It was only General Lefcourt and his ship Apollo
that saved Agamemnon's crew from martyrdom.