Although he did eventually take courses at the Howard Payne commercial school, these were business courses – stenography, typing, and a program in bookkeeping; despite his interest in history, anthropology, and literature, Howard never took college courses in these subjects. During the period from his high school graduation in spring of 1923 to his completion of the bookkeeping program in the spring of 1927, he continued writing. While he finally made his first professional sale during this period, when Weird Tales accepted “Spear and Fang,” he also accumulated many rejection slips. Further, because most of his early sales were to Weird Tales, which paid upon publication, rather than acceptance, he found that the money was not coming in as he might have liked. He therefore took a variety of jobs during these years. He tried reporting oil-field news, but found he did not like interviewing people he did not know or like about a topic that did not interest him. He tried stenography, both in a law office and as an independent public stenographer, but found he was not particularly good at it and did not like it. He worked as an assistant to an oil-field geologist, and while he did enjoy the work, he one day collapsed in the fearsome Texas summer heat, which led him to fear that he had heart problems (it was later learned that his heart had a mild tendency to race under stress), so he was just as glad when the survey ended and the geologist left town. He spent several months as a soda jerk and counterman at Robertson's Drug Store, a job that he actively detested, and which required so much of his time that he had little left over for writing or recreation. Thus he made a pact with his father: he would take the course in bookkeeping at the Howard Payne Academy, following which he would have one year to try to make a success of his writing. If at the end of that year he was not making it, he would try to find a bookkeeping job.
During the summer of 1927, Bob Howard met Harold Preece, who would be an important friend and correspondent for the next few years. It was Preece who encouraged Bob's interest in Irish and Celtic history and legend: he had earlier shown some interest in the subject, and now, inspired by Preece's enthusiasm, it would become an active passion. He also met, the same weekend, Booth Mooney, who would become the editor of a literary circular, The Junto, to which Howard, Preece, Clyde Smith, Truett Vinson, and others contributed over a period of about two years.
After completing the bookkeeping course, Howard set about in earnest the business of becoming a writer. By early 1928, it was clear that he was going to be able to succeed in this, and indeed he never again worked at any other job. Weird Tales had published two Howard stories in 1925, one in 1926, and one (plus two poems) in 1927. In 1928 they would publish four stories (including the first Solomon Kane tale, “Red Shadows”) and five poems. From January 1928 until his death in June 1936, Howard stories or verse appeared in nearly three of every four issues of Weird Tales.
Several critics have noted that Howard's writing can be divided into “periods.” Though they overlap to a degree, these periods, which seemed to last two to three years each, may reveal something about Howard's writing style and methods. The most well-defined periods are those during which he wrote boxing stories, culminating in the Steve Costigan series; heroic fantasy stories, culminating with Conan; oriental adventure stories, culminating with the El Borak tales; and western stories – he was still “in” this period at his death. A close reading of Howard's letters and stories, and placement of these along a timeline, reveals that he would develop an interest in a subject, read about it avidly, immerse himself in it so thoroughly that he virtually adopted a new identity (a persona, the “voice” through which a writer speaks, not to be confused with the writer's own personality), whereupon he would begin, at first tentatively and then with increasing confidence and vigor, to write about the subject in this new “voice.” While something of the pattern can be seen from his early writing, it is most vivid beginning with his “boxing” persona, Steve Costigan.
Howard's passion for boxing is attested as early as age nine. He boxed with his friends at any opportunity, and in his late teens may have occasionally assisted in promoting fights at local clubs in Cross Plains. While working at the soda fountain at Robertson's Drug Store, he developed a friendship with one oil-field worker who introduced him to the amateur fighters at the local ice house, and he became a frequent participant in these bouts. Between 1925 (at the latest) and 1928, he put himself through a weight and strength program, and took on really heroic proportions. He read avidly about prizefighters, and attended fights whenever and wherever he could. By early 1929 he had begun writing and submitting boxing stories, though his first efforts mingled boxing with weird themes. (This was another of his patterns: when trying out a new literary field, he would often use characters, settings or themes with which he was already comfortable.) With the first Steve Costigan story, “The Pit of the Serpent,” in the July 1929 Fight Stories, he had found a market that would prove as steady for him as Weird Tales, at least until the Depression knocked out Fight Stories and its companion magazine, Action Stories, in 1932.
The same weekend he met Harold Preece in Austin, Howard had bought a copy of G.K. Chesterton's book-length epic poem, The Ballad of the White Horse, which brings together Celts, Romanized Britons, and Anglo-Saxons under King Alfred in a battle of Christians against the heathen Danish and Norse invaders of the 9th century. Howard enthusiastically praised the poem in letters to Clyde Smith, sharing lengthy passages. It apparently inspired him to begin work on “The Ballad of King Geraint,” in which he brings together representatives of various Celtic peoples of early Britain in a valiant “last stand” against the invading Angles, Saxons, and Jutes. Chesterton's idea of “telescoping history,” that “it is the chief value of legend to mix up the centuries while preserving the sentiment,” must have appealed to Howard greatly, for this is precisely what he did in many of his fantasy adventures, particularly in his creation of Conan's Hyborian Age, in which we find represented many different historical eras and cultures, from medieval Europe (Aquilonia and Poitain) to the American frontier (the Pictish Wilderness and its borderlands), from Cossacks (the Kozaki) to Elizabethan pirates (the Free Brotherhood). Howard “mix(ed) up the centuries while preserving the sentiment”: this “telescoping” allowed him to portray what he saw as universal elements of human nature and historical patterns, as well as giving him virtually all of human history for a playground.
When Howard discovered that Harold Preece shared his enthusiasm for matters Celtic, he entered into his “Celtic” phase with his customary brio. His letters to Preece and to Clyde Smith from 1928 to 1930 are full of discussions of Irish history, legend, and poetry – he even taught himself a smattering of Irish Gaelic, and began exploring his genealogy in earnest. Irish and Celtic themes came to dominate his poetry, and by 1930 he was ready to try out this new persona with fiction. In keeping with his general tendency to use older work as a springboard to the new, he first introduced an Irish character into a story featuring two earlier creations – Cormac of Connacht is often overlooked as one of the “Kings of the Night,” overshadowed by the teaming up of Bran Mak Morn and King Kull, but the story is told from the Irish king's point of view. During 1930 Howard wrote a number of stories featuring Gaelic heroes, nearly all of them outlawed by clan and country.
In June 1930 Howard received a letter from Farnsworth Wright informing him that Weird Tales planned to launch a companion magazine dealing with oriental fiction, and asking him to contribute. This request rekindled the author's avid interest in the Orient, particularly the Middle East, and he produced some of his finest stories for the new magazine (originally titled Oriental Stories, later Magic Carpet). But while these stories were set during the Crusades, or periods of Mongol or Islamic conquests, they inevitably featured Celtic heroes.