WORK IN PROGRESS!
I will continue to expand this from time to time as I find more information.
June 1960: Jim Henson visits Disneyland and is interested in the way theme parks can bring characters to life. (cite)
April 1978: Jim and CTW discuss the idea of a theme park based on Sesame Street. The goals were to promote exercise, healthy eating and learning in a fun way. (cite)
June 27, 1979: A formal groundbreaking takes place in Middletown PA (just outside of Langhorne) with a group of children, from the New Approach Method day care. (cite)
July 30, 1980: Sesame Place opens to the public. Admission is $3.95. (cite) It is reported to be open year round. (cite) and eight months a year (cite) by different newspapers.
August 12, 1980: The Middletown township supervisors vote 5-0 to seek a declaratory judgement from Bucks County Court against the operators of Sesame Place. The township wanted Sesame Place to collect an "amusement tax" from patrons. Sesame Place contended that it was not an amusement park. (cite)
June 16, 1981: A Sarasota Herald-Tribune article states that Anheuser-Busch is considering building a Florida Sesame Place. Orlando and Ft. Lauderdale are possible locations. (cite)
1982: Sesame Place adds Crystal Climb, a geodesic climbing maze, and Automated Muppets, animatronic versions of the Sesame Street characters that tell jokes sing and laugh. This was reported in an October article so it's likely these additions didn't open until 1983. (cite)
June 18, 1982: A second Sesame Place park opens in Irving Texas. (cite)
1983: Ernie and Bert and The Honkers debut at Sesame Place. (cite)
April 30, 1983: Sesame Place in Texas kicks off it's first full season with new attractions: Sesame 500, a "big wheel racetrack", Zoom Flume and Slippery Slope. Admission is $7.50 per child, $5.50 per adult and children under 2 are free. Season passes are $25 for children and and $15 for adults.Hours are 9:30am to 8pm from April to August with weekend only hours in September and October. (cite)
1985: The Count's Fount opens. (cite)
1985: The Big Slipper opens. (cite)
January 11, 1985: The Irving Texas Sesame Place closes permanently. (cite)
1986: Sesame Streak opens. (cite)
1986: Big Bird debuts at the park. (cite)
1988: Grover and Prairie Dawn walk around characters are added to Sesame Place. (cite)
1990: A new Sesame Place in Tokyo Japan opens.
May 1990: Big Bird's Rambling River opens. (cite)
May 15, 1993: Twiddlebug land opened. Opening with the land were attractions: Mix-N-Match Twiddle Tracks, Teeny Tiny Tidal Wave and Silly Sand Slide. (cite)
August 1993: The Middletown water tower is painted with images of Sesame Place characters. (cite)
May 20, 1995: Sky Splash opens. The opening is attended by Barry Williams of Brady Bunch fame and cast members of the CTW show "Ghostwriter". (cite) (cite)
October 12, 1995: Parque Plaza Sesamo (a Mexican Sesame Place) opens in Monterrey, Mexico. (cite)
May 4, 1996: Sesame Place opens for it's 16th season. Zoe debuts as a walk-around character. (cite)
1998: Grover's Vapor Trail opens. (cite)
2002: The Middletwon water tower has vinyl images of Sesame Place wrapped on top of it. (cite)
December 31, 2006: Sesame Place Tokyo closes permanently. (cite)
2006: Dine With Me opens. (cite)
2006: Middletown Twp Supervisors approve a 10% parking tax at Sesame Place. Preferred and General Parking see a $2 and $3 increase. (cite)
2007: Sesame Place bans smoking in the park. (cite)
May 5, 2007: Sesame Place opens for it's 27th season. (cite)
May 5, 2007: Abby Cadabby debuts at Sesame Place and stars in a new show "Abby Cadabby's Treasure Hunt." (cite)
May 26, 2007: Sesame Place has it's first fireworks display. (cite)
2008: The Sunny Day Carousel debuts replacing the Big Bird Steps (the former entrance to the Big Bird Bridge.) (cite)