He was assigned to intelligence and promoted to a lieutenant, serving with that section in the American Expeditionary Force Siberia during the Russian Civil War, rather than at the European front.

He was the first American journalist to cover the 1923 Beer Hall Putsch, Adolf Hitler's failed attempt to seize power.

Roberts described working for the Post's legendary editor George Horace Lorimer as follows: "I told him my ideas, which he instantly rejected or accepted ...

"[3] Writer Booth Tarkington, a neighbor of Roberts in Kennebunkport, Maine, convinced him that he would never find the time to succeed as a novelist while working as a journalist.

Oliver Wiswell focuses on a Loyalist officer during the American Revolution and covers the entire war, from famous events such as the Siege of Boston, the Battle of Bunker Hill, the New York and New Jersey campaign through the Battle of Fort Washington, and the Franco-American alliance, to less-remembered events such as the Convention Army, the exodus to Kentucky County, the Siege of Ninety-Six, and the resettlement of the United Empire Loyalists, as well as providing a later look at both a dissolute Rogers and a frustrated Arnold among the British.

George Orwell reviewed The Lively Lady in the New English Weekly in 1936, describing it as "blood-and-thundery stuff ... chiefly interesting as showing that the old-fashioned nineteenth-century type of American bumptiousness ... is still going strong.

He and his wife Anna translated into English the French writer Médéric Louis Élie Moreau de Saint-Méry's account of his journey through America in the 1790s.

While a reporter for the Saturday Evening Post in the early 1920s, Roberts wrote many magazine articles and a book during the period immediately following World War I that urged strong legal restrictions on immigration from eastern and southern Europe and from Mexico.

[7] He wrote: In Why Europe Leaves Home, derived from his Post articles, Roberts referred to Jews as "human parasites".

[9] He was separately quoted warning against further "Semitic" immigration to America, which he feared would turn the U.S. population into a "worthless and futile" hybrid race.

Several months after the chapter was published, he began to receive mail from residents and ex-residents who were troubled that he neglected to mention many of the dishes they knew and loved from the Pine Tree State.