From a narrow common-law writ to a modern statutory tool for administrative accountability.

Tracing mandamus case law from Marbury v. Madison to today's immigration and agency-delay litigation reveals a remedy that has changed considerably in application while remaining remarkably consistent in its underlying principles.

The early period: a narrow, common-law remedy

In the nineteenth century, mandamus was applied cautiously and largely within the framework inherited from English common law, focused primarily on compelling well-defined ministerial duties owed by individual public officials.

The mid-twentieth century: codification and modern statutory grounding

The enactment of 28 U.S.C. § 1361 in 1962, along with the broader development of administrative law under the Administrative Procedure Act, gave mandamus a firmer statutory foundation and extended its reach more systematically to federal agencies, not just individual officers.

The late twentieth century: defining the outer limits

Decisions like Kerr, Will, and Allied Chemical Corp. v. Daiflon, discussed elsewhere in this section, worked to carefully define the boundary between legitimate mandamus relief and improper interlocutory appeals, cementing the "extraordinary remedy" characterization that still governs today.

The twenty-first century: the rise of agency-delay litigation

In recent decades, the explosive growth of immigration and benefits mandamus litigation has made unreasonable-delay claims — evaluated through the TRAC factors — one of the most active areas of mandamus practice, a significant shift from the writ's more individualized, ministerial-duty origins.

What the next chapter might hold

As government agencies continue to face large application backlogs across immigration, benefits, and regulatory contexts, mandamus and its close statutory cousin, the APA unreasonable-delay claim, are likely to remain central tools for holding government offices accountable to their own processing obligations.