Lin Eagan has lived in Columbia long enough to cycle through a half-dozen homes and raise two sons, who would move away as adults but return once they became parents themselves.
"Now all my grandchildren live within walking distance," Eagan says with both grandmotherly and civic pride. "It's proof of how special Columbia is."
Eagan, a real estate agent and member of the Columbia Association governing board, will be among those gathering Sunday to launch several months of events to celebrate the community's 50th birthday.
The milestone comes at a pivotal time for Columbia, which is old enough that some of its earliest neighborhoods are fraying and...