what is the fictional date?

I hear that Wanted: Dead or Alive is said to happen in the 1870s.

It would be normal, though perhaps not accurate, to assume that Josh Randall was suppsoed to be about the same age as his acter, Steve McQueen.

Steve McQueen lived from March 24, 1930 to November 7, 1980, and so was 28 years, 5 months, and 13 days old when the first episode of Wanted: Dead or Alive was broadcast on September 6, 1958, and 31 years and 5 days old when the last episode aired on March 29, 1961. And he was months younger when he acted in those episodes.

Since Josh Randall was supposed to be a ex Rebel soldier, assuming that he was about the same age as Steve McQueen was puts a limit on the possible date range of Wanted: Dead or Alive.

If Josh Randall was about 18 to 40, the typical age range for Rebel soldiers in the Civil War, during the Civil War in 1861-1865, he would have been born about 1821 to 1847, and would turn 28 in 1849 to 1875, and turn 31 in 1852 to 1878. Since Wanted: Dead or Alive is set after the Civil War, the fictional date should be some time in the period 1865-1878.

Of course Randall could have been a younger than usual soldier, maybe a drummer boy, and thus be somewhat younger, making Wanted: Dead or Alive happen somewhat later. But I guess there is no point in mentioning the theoretical latest possible dates for Wanted: Dead or Alive because nobody would believe in soldiers as young as the youngest actual soldiers in the Civil War.

I just watched (on August 8, 2018) an episode "Vendetta", first broadcast 9 April 1960, which should be dated by historic events. Six months ago Captain William Phelps's wife and baby were killed by Kiowas, driving him insane, and now he plots to invade the Kiowa reservation near South Pass and massacre many Kiowas, possibly starting a new war and plunging Wyoming into bloodshed. One of the officers mentions fighting the Kiowas for five years until the recent treaty.

So obviously "Vendetta" should be right after a five-year-long war with the Kiowas ends, right?

The Kiowa migrated south from Montana into the Rocky Mountains of Colorado in the 17th century and later into the southern plains in parts of Kansas, Colorado, New Mexico, Texas, and Oklahoma. The Kiowa made an alliance with the Comanche about 1790 and had a long standing alliance with the Kiowa Apache. The Comanche, Kiowa, and Kiowa Apache made peace and alliance with the Southern Cheyenne and Arapaho by about 1840, thus forming a large southern block of tribes often hostile to the USA.

The treaty of Medicine Lodge of 1867 established a Kiowa reservation in The Indian Territory (Oklahoma) and the hostile elements of the southern tribes submitted and went to their reservations in Indian Territory after the Red River War of 1874-75.

So in real life there never was a five-year-long war with the Kiowas and not also with the allies of the Kiowas - allies like the Kiowa Apache, the Comanche, the Southern Cheyenne, & the Arapaho - and the Kiowas never had a reservation in Wyoming near South Pass, so the events in "Vendetta" can't be used to date Wanted: Dead or Alive.

So what other events in other episodes might possibly be used to date Wanted: Dead or Alive?