Short answers, pulled from the story.
Karl Dönitz developed coordinated attack tactics based on Hermann Bauer's earlier plan during the interwar years. Trials of these new tactics in 1936 proved successful despite German naval restrictions.
Six U-boats under the command of KL Rucker operated in the English Channel and attempted to gather merchant ships into a single target area for attack. The strategy failed when U-103 was rammed and sunk by a troopship before firing torpedoes, and UB 72 was torpedoed by a British submarine.
Most notably, wolfpacks required extensive radio communication to coordinate attacks which left them vulnerable to High Frequency Direction Finder or Huff-Duff devices. Allied naval forces used this tool to determine the location of enemy boats transmitting and attack them while effective air cover allowed U-boats to be spotted.
Swede Momsen devised these tactics and led the first American wolfpack composed of USS Gato USS Sealion and USS Growler from Midway on the 1st of October 1943. This pack organized before leaving port under the command of the senior captain of the three.
Wolfpacks fell out of use during the Cold War as the role of the submarine changed with trade returning to peacetime conditions and the end of convoying. The submarine ceased to be a commerce raider and moved to traditional military roles like scouting and intelligence-gathering.