Doctor Henry "Hank" Pym began operating as the Ant-Man in 1962. He was joined the next year by his then-fiancée, Janet Van Dyne, who became the Wasp III. (Two previous Wasps, Burton Slade and Dan Burton, had been pre-war "mystery men" with no connection to Janet Van Dyne.) That same year, 1963, the two joined Thor, Iron Man and the Hulk to form the Avengers, a team which still fights crime to this day. Hank and Jan served the team on-and-off for many years, though Hank went through several aliases, including Giant-Man, Goliath and Yellowjacket II. (Pym was unaware a the time of the career of the first Yellowjacket, vince Harley.)
Hank and Jan were married in 1966, and enjoyed a long and trouble-free union. (1) In 1968, said union was blessed with a son, Harold "Hal" Pym, named for a family friend, test pilot Hal Jordan. Parenthood led the Pyms to cut back on their adventuring, and they became reserve members of the Avengers. Hank, particularly, devoted himself more to his research than to crime-fighting.
For a time (1969-1972), Pym's teammate Clint Barton operated as Goliath II, before reverting to his previous persona, Hawkeye.
The birth of Hank and Jan's daughter, Janet Pym (The Younger) in 1975, merely accelerated this process. So it was that in 1975, Hank Pym effectively passed the torch, as his former lab assistant, Bill Foster, began his career as Black Goliath. (Four years later, Foster changed his alias to Giant-Man II.) In 1979, Scott Lang began his career as the Ant-Man II, more or less with Pym's blessing. That same year, Hank and Jan had one more child, Cassandra, called "Cassie".
During a period where Bill Foster had lost his size-changing abilities (ca. 1982), a young man named Ramsey Kole who wanted to become taller broke into Foster's lab and stole some altered Pym particles. However, instead of changing into a giant, Kole became incredibly tall and lanky, assuming the name Daddy Longlegs.
Subsequently, Kole went to the criminal scientist Doctor Karl Malus who cured him but synthesized the Pym particles and used them on the ionically-charged Erik Josten (the original Power Man), turning him into the evil Goliath III. Josten later reformed, becoming Atlas of the Thunderbolts.
In 1984, when Hal Pym turned 16, it was discovered that he had somehow inherited his parents' size-changing powers. (Pym theorized that his and his wife's long exposure to "Pym Particles" had somehow affected their DNA). Hal began attending the Westchester School for Gifted Youngsters, and later fought crime as Green Goliath, a member of the X-League.
In 1986, Rita DeMara stole some of Pym's equipment, becoimgn the criminal Yellowjacket III, although she did subsequently reform..
In 1990, Scott Lang retired from crimefighting and his place was taken by his daughter Cassie, who, as the Stinger, became a long-time member of the Avengers. In 1991, the younger Janet Pym also began to exhibit size-changing powers, and she, too, began attending the Westchester School. In 1996, she joined the X-Patrol as Elasti-Girl II, named for one of the team's founders, and she still is a member today, as well as a member of the school's faculty. When Cassie Pym's powers began to develop, in 1995, she, too, began attending the Westchester School, and today fights crime as the Wonder Wasp (2) , a member of the X-League like her brother.
Hank Pym passed away unexpectedly in 1997, and the elder Janet began devoting herself completely to her career as a fashion designer. In 2005, Scott Lang's niece Cassie Lang II (3) , who had been living with him after her parents were killed, also began to exhibit size-changing powers. She attended the Westchester School, utilizing the alias "Stature". Later she spent time as an Avenger.
In 2006, amoral SHIELD agent Eric O'Grady became Ant-Man III, and Bill Foster's nephew Tom became Goliath IV. In 2015, computer technician Raz Malhotra became Giant-Man III. The next year, Nadia, a girl who claimed to be Hank Pym's grand-daughter by his first wife, became the Wasp IV. (4)
(1)As far as I'm concerned, the whole business of Hank slapping Jan around never happened in the Earth-44 universe. I'm not saying that domestic abuse is something that shouldn't be addressed in comics, I just didn't like the way it was handled with these characters.
(2)The X-League were characters that appeared briefly in one of the Access mini-series. Wonder Wasp was an amalgam of the Wasp and Cassie Sandsmark. She wasn't given a secret ID in-story, so I arbitrarily named her "Cassie Pym". It does mean that we end up with alot of Cassies here. Perhaps it was a popular name on Earth-44 in those days.
(3)I wanted to have both Stinger and Stature in the timline, and I didn't want to simply have Stature be an older Stinger with a different codename and m.o. I thought about making Stature Stinger's daughter, but the characters were just close enough in age that Stinger would have had to have had a daughter fairly young. Not impossible, but not a direction that I wanted to go in with the character. So, I went with the best I could come up with, making Cassie Scott's niece who happens to have the same name as her older cousin. Hey, I'm called "Bob" and I have cousins called "Bob" on both sides of my family.
(4)I bumped her to grand-daughter to allow for the passage of time.