(CBS) — Chicago Mayor Rahm Emanuel, in a surprise announcement, said he will not seek re-election. Here are a few fast facts about Rahm Emanuel that helped define his seven years as Chicago’s mayor.

1. CPS shakeups: In the spring of 2013, Chicago made history when the city shuttered 50 schools–a decision that displaced 12,000 students. To date, it is the nation’s largest one-time school closure. At the time, city officials explained the Chicago Board of Education’s decision to close 10 percent of CPS schools as a way to address falling school enrollment and as part of their efforts to improve the city’s struggling education system.

Critics blasted Emanuel, saying the closings would disproportionately affect minority neighborhoods and endanger children who may have to cross gang boundaries to get to a new school.

The year before the school closures, the Chicago Teachers Union, unable to reach a compromise with the city over health insurance and pay agreements, led an eight-day strike. The strike delayed the start of the school year, and made history as the first CPS strike in 25 years.

This year, A Chicago Tribune investigation revealed CPS had failed to properly screen hundreds of staff, leaving students susceptible to sexual abuse. 

2. Laquan McDonald shooting: The 2015 release of the video of Laquan McDonald’s fatal shooting caused widespread backlash that sparked protests and heightened racial tensions across the city. Emanuel was heavily criticized for waiting more than a year after the shooting to release the video. It was a move critics say was fueled by his motive to get re-elected to his second term as mayor. Surrounded by a sea of political pressure in the wake of McDonald’s shooting, Emanuel fired then-police chief Garry McCarthy. Ex-Cook County State’s Attorney Anita Alvarez lost her re-election bid. McDonald’s alleged killer, Officer Jason Van Dyke, will be tried for murder this month, and Emanuel’s announcement came on the eve of jury selection for that trial.

3. Barbara Byrd-Bennett: Emanuel appointed Byrd-Bennett CEO of CPS in 2012. Three years later, Byrd-Bennett resigned amidst bribery allegations and involvement in a kickback scheme in which she steered $23 million in contracts to her former employer. She’s now serving a 4.5 year prison sentence.

Former Chicago Public Schools CEO Barbara Byrd-Bennett (Photo by Scott Olson/Getty Images)

4. Property tax increases: In 2015, the City Council approved the largest property tax hike in modern Chicago history, with the vast majority of the new revenue going to shore up police and fire pension funds. By a 36-14 vote, aldermen signed off on a $7.8 billion budget plan for 2016, after only a few minor changes to Emanuel’s original proposal. The budget included $588 million in property tax increases through 2019; with $543 million going to police and fire pensions and $45 million going toward public school construction.

5. Chicago’s Tech Industry: Emanuel is largely known as a pro-business mayor. Tech incubator 1871 opened in the Merchandise Mart in 2012 under the influence of Emanuel, who over the years has been a frequent speaker at events hosted by the networking group.

Tech behemoths Google and Facebook both have an expansive presence in Chicago. Both companies planned big real estate moves this year, with Facebook leasing 200,000 square-feet in a new office building at 151 N. Franklin St. in the Loop. Google is reportedly also expanding its West Loop offices, and Pinterest has leased 30,000 square feet at 111 N. Canal St., in the West Loop, where it plans to move its Chicago office later this year from River North (according to Crain’s Chicago Business).

Companies with new Chicago headquarters include McDonald’s, Conagra Brands, Kraft Heinz, Motorola, Gogo, Hillshire Brands and Beam Suntory. Allstate and Walgreens have kept their headquarters in the suburbs while shifting thousands of jobs to downtown Chicago offices.

6. Riverwalk expansion and opening of the 606 Trail: Under Emanuel’s administration, the city expanded the Riverwalk and opened the 606 elevated pedestrian and bike path that runs through Chicago’s west side. Emanuel’s successor will inherit ongoing plans to expand both. The neighborhood around the 606 also experienced a sudden boom during the last few years thanks to swaths of businesses and residential developments moving

Chicago’s next mayor will also inherit other high-profile commercial projects including developer Sterling Bay’s Lincoln Yards project.

If approved, the 70-acre mixed-use project would bring a soccer stadium and office, residential and hotel towers to an industrial area in Lincoln Park and Bucktown.

7. Wrigleyville expansion: A massive makeover has changed the character of the neighborhood surrounding Wrigley Field, thanks in part to a joint-push by Emanuel and North Side Alderman Tom Tunney to bring high-density development to the neighborhood.

The 2018-19 Cubs season greeted North Side baseball fans with big changes, as Wrigleyville unveiled parts of a massive makeover several years in the making. Offseason renovations at Wrigley Field included a new 600-seat American Airlines 1914 Club behind home plate, new elevators and wider dugouts. Those renovations are part of a $750 million plan to restore and modernize Wrigley Field.

Outside the ballpark, the swanky hotel Zachary rose in the ashes of the old McDonald’s on Clark and Addison streets, and new restaurants like Big Star and Shake Shack moved in. A theater, bowling alley and two 7-Eleven stores are also expected to open in the 2.5-acre project across from Wrigley Field by the end of the year. A large portion of the new development occupies the swath of land running southeast from the Addison and Clark intersection.

8. Lucas Museum: The city lost its chances for the Lucas Museum two years ago after billionaire filmmaker George Lucas decided to take his plans to Los Angeles.

Lucas wanted to pledge $750 million to build the Museum of Narrative Art on a parking lot for soldier field, but the deal fell through due to opposition from Friends of the Parks, an organization that sought to block the museum from being built on Chicago’s lakefront.

Its fight gained traction in federal court. The mayor sought a compromise with the group by suggesting McCormick Place East be torn down to make way for the museum, but the Friends of the Parks did not endorse that option.