[5] The project was founded by former hedge fund manager and prison abolitionist Neil Barsky with former New York Times executive editor Bill Keller as its first editor-in-chief.

When writing an op-ed in The New York Times, Barsky thought it might be a good opportunity to plug the idea, so he included a brief description of the project and the website URL in his byline.

[10][16] It also publishes a weekly feature called "Life Inside," where people who work or live in the criminal justice system tell their stories in first-person essays.

[22] The Marshall Project announced that Katrice Hardy will lead both the newsroom and business operations as CEO, alongside acting editor-in-chief Geraldine Sealey.

[25] Joe Pompeo wrote of The Marshall Project that it had had a great start due to a mix of good initial publicity and association with high-profile names.

[7][26] It has been compared with the non-profit ProPublica, the Center for Investigative Reporting, Inside Climate News, and The Texas Tribune,[10][26] and also with recent for-profit journalistic experiments such as Vox and FiveThirtyEight.

[35] The Marshall Project was awarded the Pulitzer Prize in National Reporting in 2021 for a yearlong investigation into injuries caused by police dog bites.