Benjamin Harris[his mother's family name] Walker was strongly involved in the Underground RR.
He did have six sons that fought in the Civil War but it was his father Abner Walker that had 11 grandchildren in the Union Army.

Children of Benjamin Harris Walker:
[1.] Thomas Griffith Walker b. 1832
91st PA Vol. & 171st PA Vol.
[2.] Benjamin Harris Walker b. 1834 [1831?]
84th PA Vol. Co. A Corp. 57th PA Vol.
[3.] Morris Walker b. 1836
84th PA Vol. Co. C
[4.] William Allison Walker b. 1838
21st Regt. PA Vol. Cavalry
d. Jan. 4, 1864
[5.] Asahel Walker b. 1840
84th PA Vol.
[6.] Isaac Walker b. 1844

Minutes of Dunnings Creek Monthly Meeting
Fishertown Bedford Co. PA
15 Aug. 1827 Sarah [Harris] Walker & 7 children from Monallen.
Children: Benjamin H.; Rebecca H.; Ruth; Barbara H.; Sarah; Anna; Beulah

10 Nov. 1830 - Benjamin H. Walker married out of unity to non-member by Magistrate, disowned.

They had eleven children.

Book:
Chapter on the Underground RR:
Blackburn, E. Howard, and William H. Welfley. A History of Bedford and Somerset Counties, Pennsylvania. 3 Vols. New York : The Lewis Publishing Company 1906.
Bedford County by E. Howard Blackburn: Vol. 1
Pg. 376
At Bedford, help, aid and directions were given by JOHN FIDLER, ELIAS ROUSE, or JOSEPH CRAWLEY, the principal colored agents of the railroad business in town, who would arrange for the safe transport of such passengers to the Quaker settlement, where they were taken in charge by the PENROSES, WAYS, or MILLERS, who would either forward them along the usual line to BENJAMIN WALKERS's, near the mountain, or, as they occasionally did, take them directly to the Blair county line by way of Claysburg and East Freedom. From WALKER's they were generally taken across the mountain to the home of WILLIAM SLEEK, near Geistown, Cambria county and from there advanced through other trusty hands to Clearfield county and on northward. The persons most actively engaged in this business along the line were JOHN FIDLER, ELIEAS ROUSE, and JOSEPH CRAWLEY of Bedford, AMOS, SAMUEL, WILLIAM and JOSIAH PENROSE, ELI MILLER, SAMUEL WAY, WILLIAM KIRK, AMUEL K. MILLER, JOHN ALBAUGH, NATHAN HAMMOND and others, of Fishertown, and BENJAMIN H. WALKER, SAMUEL HESS, GEORGE HARBAUGH, GEORGE HESS, and JOHN HESS of Pleasantville.

Grandchildren:
Civil War Soldiers of Bedford County Pennsylvania Compiled by Kevin Mearkle; First Edition 2021; Bedford County Historical Soceity, Barnes and Noble; Amazon.
Asahel Walker 84th Infantry Company A; Age 22; Private; Mustered In 10/24/1861
Benjamin H. Walker 84th Infantry Company A; Age 30; Corp.; Mustered In 10/24/1861
Morris Walker 84th Infantry Company A; Age 25; Private; Mustered In 10/24/1861
From the same area and on the same date:
Jason Harbaugh 84th Infantry Company A; Age 18; Private; Mustered In 10/24/1861
William H. Harbaugh 84th Infantry Company A; Age 22; Private; Mustered In 10/24/1861
Frederick M. Renninger/Rininger 84 Infantry Company A; Age 17; Private; Mustered In 10/24/1861; Died (His family received one letter but thought perhaps he died at Gettysburg and was placed in an unmarked grave.) Antrietam National Cem. #4184; Died 4 March 1862.