One of the worst tornado outbreaks in the pre-1870 period in American history is the 6/3/1860 IA-IL outbreak. At least 11 tornadoes touched down and 148 people were killed making it one of the deadliest tornado outbreaks in US history. This was the climax of an active late May-early June period that included other intense/violent tornadoes in Pennsylvania and Kansas.

Newspapers usually exaggerated stuff at this time so take these descriptions with a grain of salt though I do believe that ~3 of the tornadoes from this outbreak were violent. The first major tornado from this event was the New Providence IA tornado which was probably one of the strongest tornadoes of this outbreak. The small communities of Pritchard's Grove & Quebec were devastated. In Pritchard's Grove, 7 people were killed as the entire community was devastated. A brick home was leveled, cornfields were reportedly scoured, and "the timber and every movable thing was swept away like dust before the broom." In the town of Quebec was structural damage was reportedly worse but the death total was either zero or not known. Here "not a vestige of the settlement remained where it stood. Cellar holes marked the former sites of structures which, with their contents were distributed in fragments over the wide prairie."
The next major tornado passed north of Cedar Rapids and devastated rural areas. A dozen farms were reportedly completely swept away and a sill from one of the swept away farmhouses was reportedly carried 500 ft and embedded in the ground. Some of the descriptions in this area also seem to hint towards ground scouring as "the ground was literally plowed up, covered with rails, stakes, etc., standing upright, some of them buried half their length in the ground. The grass was cut shorter than it could have been with a scythe." 9 people were killed by this tornado.
The Rogers Grove tornado was the 3rd (technically 4th but I'll talk about that tornado later) intense tornado from this outbreak. Homes were destroyed by this tornado and animal corpses were smeared with mud. Not but is known about this tornado though it killed 8 people.
The next two intense tornadoes moved parallel to each other and later underwent a merger similar to Gossell. The northernmost tornado moved through rural areas of Linn, Cedar, and Cedar Counties. Numerous homes and barns were destroyed by this "storm demon" with some reported having been completely swept away and scattered over the countryside. Wheatfields were reported to have been scoured.
The southernmost of the "twins" and the deadliest tornado of this entire outbreak began in eastern Cedar County and moved parallel to the previous event. Eventually, it merged with the tornado near Dewitt and rapidly intensified. In rural areas west of Comanche, numerous farmhouses were razed, and "beautiful homes were swept out of existence." Ground scouring may have also occurred near these areas as "In many places, plowed soil was wholly blown away, as if washed off by a freshet, and in several authenticate instances, the freshly turned prairie sod was wholly swept away." 28 people died on farms in this area. The tornado then tore through the town of Comanche which was absolutely devastated. Numerous homes and buildings were reported to have been destroyed, rail-cars were thrown, "trunks, clothing, beds, carpets and all kinds of furniture, including even stoves, absolutely vanished," and a 3-story brick hotel was reportedly leveled. 41 people were killed instantly and some likely died from their injuries later. The tornado then moved across the Mississippi River, sinking a raft (23 deaths) and crossing into Illinois. Buildings in the town of Albany were destroyed with several fatalities. The tornado then continued destroying farms in rural IL before dissipating somewhere in Whiteside County.
The last major tornado from this outbreak was a long-tracked tornado family that destroyed farms in Whiteside, Lee, and Dekalb Counties in IL. Some farms were reported to have been completely leveled and 8 people were killed.