Several Galaxy wings, made up of Galaxy-class starships, were incorporated into the Starfleet fleet assembled by Benjamin Sisko to retake Deep Space 9. This larger fleet was itself composed from elements of the Second, Fifth, and Ninth Fleets.
These Galaxy units were responsible for engaging the larger targets in the combined Cardassian and Dominion fleet.
After several waves of attack fighters opened a hole in the Cardassian front lines, it was observed that several Galor-class destroyers were positioned in such a way that any vessel that would go through the hole would be trapped.
Viewing this potential trap as perhaps being the only opportunity to break open the Dominion fleet, Sisko ordered Galaxy Wing 9-1 and Galaxy Wing 9-3 to engage the Galor-class destroyers, and effectively "hold the hole open" while all remaining ships headed through.
Once the plan was initiated, Sisko observed that two ships from these wings that were supposed to be protecting the USS Defiant's starboard flank, the USS Magellan and USS Venture, were in "too tight."
Sisko attempted to compensate by requesting the Sixth, Seventh, and Eighth Fighter squadrons to regroup and offer their support, but the Dominion had jammed their communications signal by generating a rotating E-M pulse. (DS9: "Sacrifice of Angels")