I Wish That the Wars Were All Over / I Would That the Wars Were All Done is a traditional ballad of at least eighteenth-century origin. There are basically two versions of the ballad, one presumably dating back to the American War of Independence (1775-1783) and the second probably dating back to the Flanders Campaign (1793-1795).
Both versions were collected by the Rev Sabine Baring-Gould at the end of the 19th century.

I Wish That the Wars Were All Over: It was down in the meadows where violets are blue
two sources
Timothy Connor in “A Sailor’s Songbag: An American Rebel in an English Prison, 1777-79”
Samuel Fone of Dartmoor, Devon
FOLK REVIVAL: Sam Richards ( Invitation to North America 1977-Trish Stubbs voice)
Tim Eriksen reworks (new text and new melody) the eighteenth-century version
covered by Joan Baez in "Whistle Down The Wind" 2018 and Appalachian Road Show in Tribulation 2020

I Wish That the Wars Were All Over: In the meadow one morning when pearly with dew

Text and score are printed in the Garland of Country Song (1895 pgg 18-19) (cf) by Rev Sabine Baring-Gould for which no oral source is provided.
FOLK REVIVAL: Roy Harris in The Rambling Soldier 1995
Eliza Carthy first with "The Ratcatchers" and with The Wayward Band 2017
see my post in Terre Celtiche Blog https://terreceltiche.altervista.org/i-wish-that-the-wars-were-all-over-i-would-that-the-wars-were-all-done/