By Matt Lawson, AT&T Insider 

Brian Rexroad always knew that his grandfather Carl Rumpel had worked for AT&T, but when you’re a kid you don’t think to ask exactly what “Gramp” does from day to day.

Brian followed in his grandfather’s footsteps to a career with the company – working in information security. Then, one day, when going through one of Carl’s old journals, Brian made an amazing discovery: his grandfather had a secret.

Learn about the revolutionary project from the past and the incredible coincidence that brings two generations together, more than 70 years later.