Last night Mad Men finished out the season with (SPOILER ALERT) a lot of changes that have been building up all season, and a few unexpected ones. Let's look at what we saw in last night's episode—which took place in November 1968, around Thanksgiving—and how it all compares to real life. Again, some more spoilers ahead...
HERSHEY'S
Hershey's is thinking about doing some advertising and comes in to SC&P for a pitch—at the time, the company really didn't advertise. In 1969 they hired Ogilvy and Mather (where we recently met a real Mad Man) to develop its first advertising campaign. In 1970, they launched their first media advertising campaign with television commercials for three different products: Milk Chocolate, Reese's Peanut Butter Cups, Hershey's Instant chocolate milk mix. Here's their 1972 Halloween commercial:
MILTON HERSHEY SCHOOL
During Don's meltdown, he tells the Hershey's people: "I was an orphan. I read about Milton Hershey and his school... and I read that some orphans had a different life there. I could picture it. I dreamt of it."
The school was founded in 1909, open only to caucasian male orphans, but in 1968 the school was racially integrated, and it 1976 females were accepted. The school is in Hershey, Pennsylvania, and it's still operational today.
THE CHEVY CAMARO
Pete test drives (to the best of his ability) the Camaro Z28 while at Chevy in Detroit. This commercial is Chevy's first ever Camaro commercial, which aired in the '60s—it was for the Camaro SS 350:
THE ROOSEVELT HOTEL
In Season 2 of the show, Don lived at The Roosevelt Hotel for multiple episodes, and in last night's finale Pete asks his secretary to get him a room there after his Detroit plans didn't work out and his apartment's been sublet. The hotel, which is still open, is at 45 East 45th Street, about a 10 minute walk from the SC&P offices in the Time-Life Building. 
Fun fact: From 1943 to 1955 the hotel served as the New York City office and residence of Governor Thomas E. Dewey, as his primary residence was upstate. He stayed in Suite 1527, the same room he was in when he learned he lost the presidential election to Truman.
CRUISE SHIPS
Pete lost his father to a plane crash, and now he's lost his mother to the sea. Mrs. Campbell was aboard the SS Sunset Princess when she was "lost at sea." The ship was run by Universal Cruise Line, so it likely wasn't one of the Princess Cruises, the company made famous by 1970s and '80s hit tv show The Love Boat (which featured the Island Princess and Pacific Princess).
THANKSGIVING 1968
Since Thanksgiving is in the background of the episode, here's the Macy's Thanksgiving Day Parade from the year... the year the Snoopy balloon debuted!
"BOTH SIDES, NOW"
The show ended with the Judy Collins version of "Both Sides, Now." Judy Collins first commercially released the song, written by Joni Mitchell, in 1967. In 1968 she took home a Grammy Award for Best Folk Performance for the song, which reached Number 8 on the Billboard Hot 100.
Here are all of the previous final scenes: Season 1 ended with Bob Dylan's "Don't Think Twice, It's All Right," Season 2 didn't have any music during the final scene, Season 3 ended with "Shahadaroba" by Roy Orbison, Season 4 ended with Sonny and Cher's "I Got You Babe," and Season 5's final scene was played out by Nancy Sinatra singing the theme to "You Only Live Twice."
And now, we leave you with this Vine:
