Hard as it is to believe, there is one Downtown Milwaukee building that is basically hardwired to almost every building and residence in town. That is the Wisconsin Telephone Co. (now AT&T) Building at 722 N. Broadway.

Erected in stages beginning in 1917, the steel-frame building sits atop a huge subterranean vault that connects the building’s technology floors, of which there are numerous, to substations that then connected to most every home and business in Milwaukee and, theoretically, beyond. Whether or not you still buy home phone service, that wire connection is likely still there.

Recently, I got a quick tour of the building, which was designed by no less than Alexander Eschweiler. If the exterior brickwork didn’t give that away, the multicolored stone in the fireplaces in the offices on the tops floors would have.

It’s interesting to trace the development of the building in its first dozen or so years. It went up in ‘17 as an eight-story, flat-roofed building faced with brick except on the facade of the first two floors, which was granite. There was a cornice at the top and terra cotta decorations.

The building was constructed to be expanded, according to an unsigned, undated report that AT&T’s Jim Greer gave me on the tour.

"Columns were conveniently continued through the roof where they were capped, ready for the next building phase. The stairwells were large and space was provided for six elevators. There is no indication, however, that subsequent building phases were designed" at the beginning.

In 1924, Eschweiler designed five more floors that were added to the top, plus a three-story tower (that also included a 17th level for mechanicals). Finials were added at the two west corners of the 13th floor, four smaller ones marked the corners of the tower and a lantern sat near the peak of the roof.

It was during this time that the easternmost ends of this U-shaped building were bridged at the 13th floor. Today, this bridge – inspired by Venetian gothic bridges – is a conference room with views out over Milwaukee Street. The west-facing windows have been covered up.

What’s interesting is the next expansion in 1929. While the written history says floors 17-19 were added to the tower, look at the photo above and you can see that the tower did not get additional floors. Rather, the three extra floors were added to the main part of the building below.

While the old lantern was replaced 213 feet up, the six finials were preserved and added on to the newly expanded gothic revival building.

The annex to the north was added in the early 1950s and at that time the original two-story street-level facade of 722 was removed and replaced with the one you see today.

Some details survive inside. There’s a sturdy iron staircase in the north wing and some marble work, along with the fireplaces. But, sadly, most ceilings have been dropped and most other detail work is lost, as is what was once described as "the extravagantly decorated lobby."

Nowadays, the lobby is fairly small, not especially lavish and perhaps its most interesting feature is the ‘80s-era telephone booth that survives.

The once-skylighted first-floor courtyard now has an opaque roof.

But the interior changes are to be expected in a building like this. It is still the epicenter for telecommunications in Wisconsin and technology changes have led to many interior alterations.

"(Most people) absolutely don’t understand it what’s behind it," says Greer. "Everyone just wants to pick up the cellphone, hit the button and have it work. There’s a lot of technical stuff ... we have so much technical stuff going in and out of this building."

Consequently, it’s a high-security place and you’ll be as unsurprised as I to learn that I was unable to gain access to the cable vault and other tech sites.

"This is the largest central office technical wire line telephone facility in the state of Wisconsin and so there’s a cable vault, there’s equipment downstairs," says Greer, in an 18th floor office that offers fine views not only of Downtown, but especially of Eschweiler’s lovely finials and the elaborate terra cotta work.

"Over time that equipment has gotten smaller as technology gets better. But there’s still a need for the wire line at work. We sell U-Verse television over it, high-speed internet travels over it. We’re still investing in that and in our wireless network. We spent $140 million in the first six months of the year in Wisconsin."

Maybe someday I’ll get a peek into the vault and if they let me, I’ll share it with you.