Insignia Description
A gold color metal and enamel device 1 5/32 inches (2.94cm) in height overall consisting of a shield emblazoned: Per bend Gules and Azure, on a bend or a bendlet Argent indented of seven counter indented of the same fimbriated Sable, the shield surmounting a gold color metal oval belt with three blue enamel stripes parallel to the edges of the oval and surmounted by a plain gold color metal buckle in base and a gold color metal band on each side of the shield bearing the motto "SEMPER" on the dexter band and "PRIMUS" on the sinister band in red enamel letters.

Symbolism
The regiment was organized in 1791 as the 2d Infantry. In 1792 it was designated as the Infantry of the 2d Sub-legion. In 1796 it was again designated as the 2d Infantry. In the consolidation and reorganization of the Army in 1815 it was designated the 1st Infantry. The regiment has a history of fighting in all the wars of the country and a logical grouping divides its campaigns or wars into 14 groups. These are heraldically represented by the 14 notches on the diagonal band across the shield. The upper part of the shield is red, this was the color of the old 2d Sub-legion. The lower part is blue the modern Infantry color. The motto long in use by the regiment is self-explanatory.

History
The distinctive unit insignia was originally approved on 8 September 1923. It was amended on 4 Nov 1999 to add the symbolism and the metric measurements.

Source: The US Army Institute of Heraldry