Mid 1800s is a somewhat variable time period. America is a big country.
So, it is hard to give you an answer other than a quick skim through the history and a general impression.
There were Native American attacks on settlers from almost the earliest colonial times until the last Indian Raid in the US in 1924 (Apaches from Mexico raiding into Arizona to steal horses).
Although there were various sporadic attacks and isolated raids, most of the attacks on settlers coincided with or led to campaigns, wars or battles against the Indians.
By looking at the wars and battles one can see where and when the most intensive attacks on settlers were likely to be taking place.
East of the Mississippi, there were three large Indian wars after 1830. The Black Hawk war of 1832 saw Black Hawk and his 'British Band' of Sauk (and others) fighting against the US army, militia, and various other Indian groups.
During the course of this war, 77 white settlers, militia men and soldiers were killed (directly by Indians, not counting those who died of diseases etc.). Some 450-600 (about half) of the British Band perished in the conflict (though this counts those who died of diseases and the more than 100 who drowned trying to flee across the Mississippi River, and the 118-128 who were killed by Dakotas and Ho-Chunks after they escaped across the Mississippi).
Abraham Lincoln, Zachary Taylor, Winfield Scott, and Jefferson Davis, all fought in this small war.
In 1836, the Creek War broke out in Alabama. The Creeks raided settlers. There were clashes with the US army. The Creeks were removed to Indian Territory west of the Mississippi.
From 1835-1842, the Seminoles fought the Second Seminole War, in Florida, which was the longest and costliest war fought against Native Americans by the US government.
Andrew Jackson tried to remove the Seminoles to Indian Territory, to clear the way for settlers. The Seminole resisted.
The US Army had some 270-330 men killed in action (three times as many died from disease). There was an estimate of 80 civilian settlers killed. Seminole casualties are unknown.
By 1842, the war was winding down, and the majority of the Seminoles had accepted relocation to the West. Some 1,500 Seminoles, however, never made peace and remained in Florida.
https://en.wikipedia.org/?title=American_Indian_Wars
West of the Mississippi, the Comanches continued their long practice of raiding into Texas and Mexico. They killed and captured many settlers and attacked farms, settlements, cities (all the way to the coast of Texas, where they shot up Victoria and burned Linnville, the second largest port in the Republic of Texas.
After many wars and battles, in June 1875, Quanah Parker, and his band of Comanches surrendered, and that was the end of the Comanche threat to settlers on the southern plains.
A little farther west, the Navaho and Apaches raided settlers and fought many wars and battles against the US army until as late as 1924.
In the Great Basin, the Shoshone raided wagon trains and Mormon settlers until defeated at the Bear River Massacre of 1863.
The Pacific Northwest, saw the Cayuse War, Yakima War, Puget Sound War, Rogue River Wars, Snake War, Naz Perce War, Bannock War, and Sheepeater War.
These started with the Whitman Massacre in 1847, when missionary Marcus Whitman, his wife and 12 others were massacred by the Cayuse, after they blamed him for being unable to cure an epidemic of measles which was afflicting their tribe.
Conflict between settlers and Natives in the Pacific Northwest ended with the Sheepeater War in 1879, when a group of Shoshone (known as the Sheepeaters) were accused of killing 12 or more settlers and stealing horses. They were hunted down by the Army and forced to surrender.
On the Northern plans, conflict started with the Dakota War of 1862. The Sioux, led by Chief Little Crow, raided into Minnesota killing more than 500 US soldiers and settlers. The US army drove the Sioux back into the plains and fought 3 major battles, before defeating them in 1864.
That same year, the Colorado War broke out in response to a series of Indian attacks on settlements. The Colorado militia responded with the Sand Creek Massacre, killing 200 Cheyenne and Arapaho including many women and children. The Indians retaliated by attacking Julesburg and raiding and killing settlements all along the South Platte River. In 1865 the Indians continued raiding, mostly travelers on the Oregon Trail.
Sporadic warfare followed until the Great Sioux War of 1876-1877 this is the war that saw Custer’s Last Stand at the Battle of the Little Bighorn. This war was almost the end of Indian raiding on the Northern Plains, though in 1890, Army alarm at the “Ghost Dance” movement among the Sioux led to a decision to disarm some Sioux bands, which went wrong and resulted in the Wounded Knee Massacre, where circa 300 Sioux including 200 women and children were killed (as were 31 soldiers).
So, there were Native American attacks on settlers pretty much throughout the mid 1800s, and in many parts of America.
Attacks were common, but they were also sporadic, and usually involved a fairly low number of casualties. Probably more soldiers and militia were killed by Native Americans as they tried to retaliate for, or defend against attacks, than settlers were killed in raids and attacks.
(Of course there were also probably various attacks on Native Americans by settlers, though the settlers did not tend to raid in the same way that the Indians did.)