By the time he began working in the film industry, Yost already had more than a decade of stage experience in hundreds of dramatic and comedic roles and was widely regarded in the theatre community "as one of the country's finest stock actors".

[1] Reportedly, to reduce the risk of tarnishing his reputation as a professional actor by being identified as a screen performer, Yost often billed himself as "Barry O'Moore" while working in films.

[3] The following year, the decennial federal census documents the Yost family living in northern Kentucky, in Covington, where Herbert's father owned and operated a prosperous retail grocery and a dry goods store.

[4] Harry, in fact, guided or "sponsored" his little brother's entry into performing on stage by getting Herbert a job in 1897 with the Murray-Hart Comedy Company, which specialized in "one-night stands".

[4] After one full season working for Murray-Hart, Yost joined the Frost Stock Company and did a multitude of jobs in its traveling shows for a salary of six dollars a week ($200 today).

[4] He portrayed several characters in the company's staging of The Three Musketeers and The Two Orphans, and was responsible as well for entertaining audiences by playing the piano before each show, during intermissions, and giving concerts following every performance.

[6][7] Yost therefore adopted the name Barry O'Moore during his early years as a film actor to distinguish his screen work from his stage career, allegedly in an effort to conceal his identity and, at least to some degree, to distance himself professionally "from the shame of the cinema".

In October 1908, Yost joined the growing number of "photoplayers" at the Biograph Company, which then had its headquarters and main studio inside a sprawling, renovated brownstone mansion at 11 East 14th Street in Manhattan.

Intertitles provided audiences with some context for storylines, but Yost, like other screen actors of that period, had to convey his characters' intent and emotions solely through facial expressions, hand gestures, and by other subtle and exaggerated body movements.

After Yost performed in two other supporting roles, in The Fascinating Mrs. Francis and The Brahma Diamond, Griffith assigned him to star in the 1909 short Edgar Allen Poe [sic].

[e] Released by Biograph on February 8, the historical drama, which has a running time less than seven minutes, is loosely based on actual events in the life of the 19th-century American writer and poet.

[19] Shortly after completing the latter film, the now-experienced screen actor signed a contract to work for Edison Studios, also located at that time in New York City, in the Bronx.

[21] Yost's greatest film success credited as O'Moore and his most notable casting while working at Edison occurred in 1914, when he starred in a dozen comedy shorts portraying the "amateur detective" Octavius.

Characterized as a wealthy young man and a "gentle and genial idiot", Octavius was presented as having "sublime confidence in his own marvellous [sic] ability as a sleuth" to solve crimes and mysteries.

Variety in its December 31, 1915 assessment of Over Night focuses special attention on cast members "Herbert Yost and Sam B. Hardy", the "two comedians" who in the trade paper's opinion "take the picture along.

"[25] Yost spent the vast majority of the final 30 years of his career acting on stage, but he did return very briefly to films during the early sound era.

[11][12] After the release of his first two shorts for Edison in 1909, Yost soon embarked on a tour to perform with his future wife Agnes Scott in The Wall Between, a "sentimental playet" that they presented at the Grand Opera House in Indianapolis, the Majestic in Chicago, the Orpheum in Harrisburg, Pennsylvania, and at other major theatres.

In an assessment of the production's premiere, The New York Times focused special attention on the performances of two cast members, noting that the players "who seemed to win from the audience the most favor were Margaret Lawrence and Herbert A.

"[29] In another Manhattan review, the New York Tribune found Over Night "commonplace" but, like The Times, complimented Yost's portrayal of the "bashful bridegroom" Richard Kettle as one of the bright, "amusing" parts in the production.

[32] The newspaper also reported, "The most distinguished performance of the evening is given by Herbert Yost", adding that "He plays throughout with a complete understanding that is reflected in every slightest tone and gesture.

[33] Two years later he made his final stage appearances as the "Tragic Gentleman" in the three-act comedy Jacobowsky and the Colonel co-starring Louis Calhern, Oskar Karlweis, and Annabella.

In that capacity he convened meetings at the Unity Center in New York City and later established near his home in Old Greenwich an affiliated chapel, where he often conducted services and hosted related events.

[39] According to his obituaries, in Manhattan on the evening of October 22, 1945, Yost failed to meet his wife Agnes as planned at the 46th Street Theatre following her performance there in the play Dark of the Moon.