On the night of March 28–29, 1984, Robert Irsay, then-owner of the Baltimore Colts of the National Football League (NFL) covertly moved the team to Indianapolis, Indiana, where it would begin play as the Indianapolis Colts in the 1984 NFL season.

The city government of Baltimore, Maryland, had proved unwilling to replace the team's three-decade-old home stadium, and the Maryland General Assembly was on the verge of passing legislation allowing the city to seize the team via eminent domain. The move embittered many Baltimoreans for decades. Its effects on the NFL include a similar controversy that 12 years later brought Baltimore its current franchise, the Ravens.

Actions leading up to the move

The Colts had played at Baltimore Memorial Stadium since the 1953 NFL season, sharing the facility with Major League Baseball's Baltimore Orioles. In May 1969, the city of Baltimore announced it would seek a substantial increase in Memorial Stadium rental fees from Colts owner Carroll Rosenbloom and the team itself. Rosenbloom had already called the stadium "antiquated" and had threatened to stop playing there unless improvements were made. Rosenbloom even considered using $12 million to $20 million of his own money to help fund the building of a new football-only stadium on land in adjoining Baltimore County. In November 1971, Rosenbloom announced that the Colts would not return to Memorial Stadium when their lease ran out after the 1972 season and that he was no longer interested in negotiating with the city. He wanted out of Baltimore for several reasons: team revenue, disputes with Baltimore Orioles owners over stadium revenue, a running feud with the Baltimore press, and his new wife's desire to move to the West Coast. After the 1971 season, Rosenbloom and Irsay swapped teams, the former taking ownership of the Los Angeles Rams and the latter the Colts.

In 1971, Baltimore mayor William Donald Schaefer and Maryland governor Marvin Mandel created a committee to examine the city's stadium needs. Their report was a blow to Memorial Stadium. Some of the problems mentioned: 10,000 of the stadium's seats had poor views of the field; 20,000 seats were outdated bench seats without back support; 7,000 seats were poorly constructed temporary bleachers that were installed for football games only. There was not enough office space for the front offices of either the Orioles or Colts, much less both teams combined. The teams had to share locker rooms. The upper deck of Memorial Stadium did not circle the field, ending instead at the 50-yard line. Any expansion plans for the stadium had usually mentioned less attractive (and less expensive) end-zone seats, not upper-deck seating. Even the bathroom facilities were deemed inadequate.

Baltodome project Maryland's planners proposed the Baltodome, a facility near the city's Inner Harbor known as Camden Yards. The new stadium would host 70,000 fans for football games, 55,000 for baseball, and 20,000 as an arena for hockey or basketball. For an estimated $78 million, the city would build a facility that would have kept all parties happy: Baltimore Mayor Schaefer, Governor Mandel, Orioles owner Jerold Hoffberger, Colts owner Irsay, and the Stadium Complex Authority, whose chairman, Edmond Rovner, said in 1972, "A major consideration in Mr. Irsay's trading of franchises was the city's firm commitment to proceed with these plans".

However, the proposal did not receive support to pass the Maryland legislature, in spite of assurances that contributions from taxpayers would be limited strictly to city and state loans. On February 27, 1974, Mandel pulled the plug on the idea. Hoffberger was blunt: "I will bow to the will of the people. They have told us what they want to tell us. First, they don't want a new park and second, they don't want a club." Irsay was willing to wait. "It's not a matter of saying that there will be no stadium. It's a matter of getting the facts together so everybody is happy when they build the stadium. I'm a patient man. I think the people of Baltimore are going to see those new stadiums in New Orleans and Seattle opening in a year or two around the country, and they are going to realize they need a stadium...for conventions and other things besides football."

Hyman Pressman, Baltimore's comptroller, was against using any public funds to build a new stadium. During the 1974 elections, Pressman had an amendment to the city's charter placed on the fall ballot. Known as Question P, the amendment called for declaring "the 33rd Street stadium as a memorial to war veterans and prohibiting use of city funds for construction of any other stadium." The measure passed 56 percent to 44 percent, and the same political motivations that had been used to upgrade Baltimore Stadium, originally built in 1922, in the late 1940s and rename it Memorial Stadium, effectively destroyed any chance of a new, modern sports complex being built in Baltimore.

1975–1980 Although the Colts made the playoffs for three straight years from 1975 to 1977, there had still been no progress made on a new park for the team. Robert Irsay first spoke with Phoenix, Arizona, in 1976 and then Indianapolis, Indiana, in 1977 about the possibility of moving his team to one of those cities. In 1976, he acknowledged publicly that he had received an attractive offer to move the franchise to Phoenix. Then, in 1977, he said, "I like Baltimore and want to stay there, but when are we going to find out something about our stadium? I'm getting offers from towns like Indianapolis to build me a new stadium and give me other inducements to move there. I don't want to but I'd like to see some action in Baltimore." In 1979, Hoffberger sold the Orioles to Washington, D.C. attorney Edward Bennett Williams, who declared 1980 to be a trial year for the fans of Baltimore. He then went on to explain his concerns with Memorial Stadium, saying it had "inadequate parking and inadequate access and egress. Frankly, I don't know if those problems will ever be solvable at that location."

Irsay began shopping the Colts around in earnest, talking first to officials from the Los Angeles Memorial Coliseum Commission, Memphis, Tennessee, and Jacksonville, Florida, where he visited the Gator Bowl packed with 50,000 cheering fans trying to convince him that Jacksonville would be the best home for the Colts. That same year Irsay presented Maryland Governor Harry Hughes with a request for $25 million in renovation to the 64,124 seat Memorial Stadium. Irsay's request for $25 million in improvements was decreased to $23 million by the Maryland legislature. The plan added more seats (but none of the revenue-generating skyboxes), improved the plumbing, and gave both teams better office space. The plan's approval was contingent on both the Colts and Baltimore Orioles signing long-term leases. The Orioles challenged the requested football improvements and refused to sign anything more than a one-year lease. Irsay also refused to sign long term. As a result, the funds and improvements never came.Euchner, p. 108.

Move to Indianapolis In the middle 1970s when the NFL was planning its expansion from 26 to 28 teams — an agreed part of the NFL/AFL merger — Indianapolis was one of ten cities considered. It was considered a strong candidate because it was located at the junction of more major highways than any other city and had a large population in both the metropolis and surrounding rural areas. However, when the final decision was made in 1974, Indianapolis was rejected because, as Dan Rooney of the Rooney family, who owned the Pittsburgh Steelers, emphasized, "We had no choice [but to remove Indianapolis from the list of expansion candidates]. Indianapolis had no suitable stadium."

Under the administration of Mayor Richard Lugar and then continuing with successor, William Hudnut, the city of Indianapolis was making a serious effort to reinvent itself into a "Great American City." From the early 1970s through the 1980s, Indianapolis businessman and civic leader Robert V. Welch was instrumental in leading the way to build consensus among NFL hierarchy and Indianapolis community leaders that Indianapolis could support an NFL franchise.Smith, Samuel (January 17, 1984). "Indy's NFL Founding Father Sent to the Sidelines". Chicago Tribune. p. 8. Retrieved July 15, 2021.Bell, Steve (April 2, 2014). "Flashback: The Colts Come to Indy—30 Years Later". Indianapolis Monthly. Retrieved July 15, 2021. As a result of this and many other initiatives, Indianapolis community leaders created the Indiana Sports Corporation in 1979 to attract major sports events to central Indiana. With respect to the NFL, Welch spent more than a decade to position Indianapolis as the NFL's leading choice for franchise expansion with Welch as the local owner and as such, Hudnut appointed a committee in 1980 to study the feasibility of building a new stadium that could serve primarily as a boon to the city's convention business and, secondarily, as a lure for an NFL team.

Construction of the Hoosier Dome begins In 1982, construction of the Hoosier Dome (later renamed the RCA Dome) began. Deputy Mayor David Frick, who later led the negotiations with the Colts and then went on to become chairman of the Indiana state commission that oversaw construction of the RCA Dome's replacement, Lucas Oil Stadium, later said that the RCA Dome was a key to changing the city's image. "Sports was an element in our game plan to change the image of the city back in the late 1970s, early 1980s."

Baltimore reportedly did offer Irsay a $15 million loan at 6.5%, a guarantee of at least 43,000 tickets sold per game for six years, and the purchase of the team's Owings Mills training facility for $4 million.

Negotiations with Phoenix and Indianapolis On March 2, 1984, NFL owners voted to give Irsay permission to move his franchise to the city of his choosing. Irsay continued discussions with several cities hungry for an NFL franchise including Phoenix, Indianapolis, Jacksonville, Memphis, and Birmingham. Even New York City made overtures to Irsay, because while it had two NFL teams nominally representing it, both no longer played in the city or state of New York after the Jets had left Shea Stadium to join the Giants in Giants Stadium in New Jersey. Eventually, Irsay narrowed the list of cities to two, Phoenix and Indianapolis. In January 1984, Baltimore mayor Schaefer stated, "We're not going to build a new stadium. We do not have the bonding capacity. We don't have the voters or taxpayers who can support a $60 million stadium. One-third of the people in Baltimore pay taxes. Unless private enterprise builds it, we won't build it."

The Phoenix Metropolitan Sports Foundation, headed by real estate developer Eddie Lynch, along with Arizona Governor Bruce Babbitt and other top Arizona officials, had secretly met with Irsay early in January 1984. Preliminary talks seemed promising. Phoenix was offering a below market rate $15 million loan and rent-free use of the 71,000–seat Sun Devil Stadium on the campus of Arizona State University. A second meeting was scheduled between Irsay and the Phoenix group. But when word of a second scheduled meeting leaked out and was reported by the media on the Friday before the Super Bowl, Irsay canceled.