The Henslow's sparrow (Ammodramus henslowii) is a small passerine bird that breeds in the eastern and midwestern United States and southern Canada and winters in the mid-Atlantic and Gulf Coast States. Its breeding range extends from New England and southern Ontario through the Great lakes region and north-central States to South Dakota, Kansas, and Oklahoma. Its winter range extends from northern South Carolina to central Florida and eastern Texas. The Henslow's sparrow is considered to be a species of special concern, as its population has declined significantly across its range. This species historically nested in tallgrass prairie. Optimal breeding habitat consists of tall, dense, grassy vegetation interspersed with forbs and occasional shrubs. Typical habitat includes restored tallgrass prairie, idle grasslands, pastures, meadows, and hayfields with dense cover. Wintering populations of Henslow's sparrow have been documented on three military installations in the southeastern United States; installations in the midwestern and northeastern United States should benefit most from this report because the sparrow's decreasing breeding range is located in these regions. This report is one of a series of Species Profiles being developed for threatened, endangered, and sensitive species inhabiting plant communities in the southeastern United States. The work is being conducted as part of the Department of Defense (DoD) Strategic Environmental Research and Development Program (SERDP). The report is designed to supplement information provided in plant community management reports for major United States plant communities found on military installations. Information provided on the Henslow's sparrow includes status, life history and ecology, habitat requirements, impacts and causes of decline, habitat assessment techniques, inventory and monitoring, and management and protection.