[2][3][4] On December 18, 2018, it was reported by the Chicago Sun-Times that the team was preparing to launch its RSN, "Marquee", in 2020, and that Sinclair Broadcast Group was a frontrunner to serve as managing partner.

[5] Sinclair had previously attempted to purchase WGN's parent company Tribune Media, and ran the national sports network Stadium with the White Sox's investment arm Silver Chalice, prior to selling its stake to Silver Chalice in 2023.

[6][7] On May 22, 2019, Michael McCarthy was named general manager of the Marquee Sports Network after being the Cubs' consultant on the channel.

[8] He is the former president of the MSG Network[8] and a former top official with the Milwaukee Bucks (COO) and the St. Louis Blues (vice chairman).

Alongside its new play-by-play voice Jon Sciambi, the network would no longer require commentators to wear a suit and tie on-air (a mandate made during the inaugural season by executives insisting that Marquee's broadcasts have a "national network quality"), and replaced an unorthodox bottom-centered score bar it had used during the first season with a more traditional scoreboard in the top-left of the screen (a move which also differentiated Marquee from its newly-relaunched sister networks in the Bally Sports group, whose on-air branding was derived from that of Marquee, but with an equally-unorthodox integration of a scoreboard and ticker).

[23] On May 1, 2019, it was reported that David Kaplan—NBC Sports Chicago studio host for Cubs games—had renewed his contract with the channel, dispelling rumors that he planned to join Marquee.

[1] After the 2020 season, Kasper left the Cubs and Marquee to become the radio voice of the Chicago White Sox on WMVP.

[26] Jon Sciambi, then a television and radio play-by-play voice on ESPN's MLB national broadcasts, was hired to replace Kasper.

[1] Upon the announcement of the channel, the network's ability to gain carriage was compared to the troubled negotiations of the Los Angeles Dodgers' SportsNet LA.

[37] Industry observer Phillip Swan thought Marquee would have a "50-50 chance of working" while commenting "How can you not look at the disaster of the SportsNet (LA) scene and not be a little skeptical?

[40] On October 17, 2019, AT&T agreed to carry Marquee on its television services (including DirecTV, the second largest provider serving the region behind Comcast) as part of a larger, multi-year carriage agreement with Sinclair.

[42] In October 2024, it was reported that the channel had not yet reached a new deal with Comcast after its four-year agreement had expired, and had continued to be carried through short-term extensions.