When Season Two of Unbreakable Kimmy Schmidt premiered on April 15, it was hard to miss all the Mad Men references—no matter how quickly you binged through its 13 episodes. But this is hardly the first time Tina Fey has paid tribute to the classic AMC drama, or vice versa. 30 Rock, Mad Men and Unbreakable Kimmy Schmidt actually have a pretty long history of references, shared cast members and other connections. Here are some of our favorites.

Note: this list contains spoilers.

In Season Three’s “The Ones,” 30 Rock’s Kenneth drops this bombshell—an obvious reference to Don Draper’s true identity—right before he passes out after being poisoned by Jenna.

In Season Four’s “The Moms,” Liz Lemon is shocked to learn that her mom settled for her father after turning down a proposal from her true love, Buzz Aldrin (thankfully—can you imagine how that’d complicate Liz’s “Astronaut Mike Dexter” fantasies?). She explains herself by saying, “It wasn’t that simple, Liz. I had just graduated from secretary school, and I got a job at Sterling Cooper.”

In the 30 Rock series finale, Liz is briefly concerned that her friend/mentor Jack is going to kill himself and tries to stop him by crying, “Wait! There’s so much to live for! Don’t you want to know how Mad Men ends?” Weirdly enough, when Mad Men did end years later, it featured a similar—though admittedly way more dramatic—scene with Peggy concerned that her friend/mentor Don was going to kill himself.

Another A+ reference to the Mad Men finale—this time after the fact. In Season Two, Unbreakable Kimmy Schmidt takes advantage of the fact that Jon Hamm plays the reverend who kidnapped Kimmy and the other mole women—and a thousand internet theories about Mad Men and Kimmy Schmidt existing in the same universe are born.

Matthew Weiner was notorious for being a stickler for details on Mad Men, making sure every last prop or reference was historically accurate. So when Mad Men snuck in a subtle 30 Rock reference in Season Six’s “To Have and To Hold” by having Ted order an “Old Spanish”—a fictional drink invented by Matthew Broderick’s character on the show that consists of “red wine with tonic water and olives”—it was all the more amazing. (Sidenote: Of course it’s Ted who would drink an Old Spanish.)

The Old Spanish made its second appearance in the Tina Fey universe this year on Kimmy Schmidt, with Lillian holding what appears to be a canned version of this gross concoction. Do the olives come in the can, or are they sold separately?

On Mad Men, Sam Page played Greg, Joan’s horrible rapist/husband who abandons her for the Army. On Season Two of Kimmy Schmidt, he’s got another redheaded love interest—and his character is an Army veteran. That can’t be a coincidence, right?

Anna Camp is hilarious this season on Kimmy Schmidt as Jacqueline’s nemesis, Deirdre Robespierre. But Mad Men fans will recognize her as Bethany Van Nuys, the woman Don briefly dates in Season Four after his divorce with Betty.

No portrayal of a surly teen on TV was as simultaneously realistic and devastating as Kiernan Shipka’s Sally Draper, so of course she was the perfect choice to play Kimmy’s younger stepsister, Kymmi, in Season One of Kimmy Schmidt. Just look at that scowl.

He’s yet to make an appearance on Kimmy Schmidt (fingers crossed for Season Three), but John Slattery stepped out of his Roger Sterling role in a big way when he guest-starred in Season Five of 30 Rock. He played Steve Austin, the insane New England politician running to restore “the Founding Fathers’ America: no paved roads, rum used as an anesthetic, legal slavery.” Yikes.

We’ve already mentioned Jon Hamm’s role as Reverend Richard Wayne Gary Wayne on Kimmy Schmidt, but he also made many memorable appearances on 30 Rock. Who can forget the dumb-as-a-rock Dr. Drew Baird, one of Liz’s love interests, who eventually winds up with two hook hands as a result of his ineptitude?

Zosia Mamet’s probably best known as Shoshanna on Girls, but let’s not forget her stint on Mad Men as Peggy’s hip photographer friend, Joyce Ramsay, in Seasons Four and Five. She also crops up in Season Two of Kimmy Schmidt as one half of a hipster couple from Austin looking to move in and gentrify the neighborhood.

30 Rock’s live episode was great for many reasons, but the true highlight was Paul (Will Forte) descending from the rafters to serenade Jenna with “Zou Bisou Bisou,” an obvious nod to Megan’s classic Season Five performance of the French song for Don’s birthday party on Mad Men.

Actor Mike Carlson has popped up both on 30 Rock and Kimmy Schmidt as Mikey, the catcalling construction worker. He catcalls Liz on 30 Rock, and Kimmy on Season One of Kimmy Schmidt—but in season two, there’s a twist. He catcalls (and then ultimately falls in love with) Titus. Things seemed to be getting pretty serious for the two, with Mikey even coming out to his parents and the two eventually talking about moving in together, so here’s hoping we see more of Mikey in Season Three.

Okay, so this one’s not necessarily a Mad Men reference per se, but it is a pretty funny mention of the actress we all know as Betty Draper, made when Jacqueline calls her parents in South Dakota on Kimmy Schimdt and is on the receiving end of this exciting news.

Spoiler alert if you haven’t yet finished Season Two of Kimmy Schmidt, but it ends on a cliffhanger, with the Reverend (again, played by Jon Hamm) calling Kimmy from jail and dropping this bombshell: “Kimmy, it’s Dick. I have the most wonderful news. I met someone and I’m getting married. So you and me are gonna have to get a divorce.” Sure, Dick is short for Richard, the Reverend’s first name, but the fact that he introduces himself that way seems like an obvious Dick Whitman reference. This is particularly interesting when you consider how the whole scene is reminiscent of the flashback in Season Two of Mad Men, where we see Don (or Dick, to Anna Draper) ask Anna for a divorce on Christmas Eve so that he can marry Betty, with whom he’s fallen in love.

This is Liz’s attempt at role-playing, but it’s also a pretty accurate description of her dynamic with Criss.

The hilariously terrible Bitch Hunter, a show within the 30 Rock universe, contains this Easter egg of a writing credit. The Sopranos, Mad Men, Bitch Hunter? Nobody’s perfect—not even Matthew Weiner.