ently ▁in ▁Scotland ▁for ▁public ▁duties . ▁ ▁United ▁States ▁ ▁Washington , ▁D . C . ▁ ▁The ▁ 3 rd ▁U . S . ▁Infantry ▁Regiment ▁is ▁an ▁official ▁cer emon ial ▁unit ▁of ▁the ▁United ▁States ▁Army , ▁and ▁has ▁provided ▁the ▁esc ort ▁for ▁the ▁President ▁of ▁the ▁United ▁States , ▁as ▁well ▁as ▁formally ▁provides ▁security ▁for ▁Washington , ▁D . C .. ▁Public ▁duties ▁performed ▁the ▁by ▁the ▁regiment ▁includes ▁cer emon ies ▁at ▁the ▁White ▁House , ▁the ▁Pent agon , ▁and ▁other ▁national ▁cer emon ies ▁throughout ▁the ▁capital ▁and ▁its ▁neighbour ing ▁areas . ▁ ▁The ▁guard ▁also ▁provide ▁military ▁esc ort s ▁for ▁military ▁fun er als ▁at ▁Ar ling ton ▁National ▁C emetery , ▁and ▁a ▁perpet ual ▁sent ry ▁at ▁the ▁T omb ▁of ▁the ▁Un known ▁Sold ier ▁since ▁ 1 9 4 8 . ▁Other ▁service ▁branches ▁of ▁the ▁United ▁States ▁Ar med ▁Forces ▁also ▁maintain ▁their ▁own ▁units ▁for ▁public ▁duties ▁in ▁Washington . ▁ ▁Other ▁states ▁The ▁United ▁States ▁Army ▁installation , ▁Fort ▁Hu ach uca , ▁maintain s ▁a ▁cer emon ial ▁caval ry ▁tro op ▁known ▁as ▁B ▁Tro op , ▁ 4 th ▁Caval ry ▁Regiment . ▁It ▁is ▁one ▁of ▁only ▁four ▁remaining ▁in ▁the ▁Army , ▁and ▁is ▁mounted ▁cer emon ies , ▁par ades , ▁and ▁public ▁relations . ▁B ▁Tro op , ▁ 4 th ▁Caval ry ▁Regiment ▁res ides ▁at ▁the ▁main ▁post ▁st ables ▁and ▁conduct s ▁events