Adler & Sullivan (1888–1893)

Wright did not get along well with Sullivan's other draftsmen; he wrote that several violent altercations occurred between them during the first years of his apprenticeship. For that matter, Sullivan showed very little respect for his employees as well. In spite of this, "Sullivan took [Wright] under his wing and gave him great design responsibility." As an act of respect, Wright would later refer to Sullivan as Lieber Meister (German for "Dear Master").He also formed a bond with office foreman Paul Mueller. Wright would later engage Mueller to build several of his public and commercial buildings between 1903 and 1923.
On June 1, 1889, Wright married his first wife, Catherine Lee "Kitty" Tobin (1871–1959). The two had met around a year earlier during activities at All Souls Church. Sullivan did his part to facilitate the financial success of the young couple by granting Wright a five-year employment contract. Wright made one more request: "Mr. Sullivan, if you want me to work for you as long as five years, couldn't you lend me enough money to build a little house?"With Sullivan's $5,000 loan, Wright purchased a lot at the corner of Chicago and Forest Avenues in the suburb of Oak Park. The existing Gothic Revival house was given to his mother, while a compact Shingle style house was built alongside for Wright and Catherine.
According to an 1890 diagram of the firm's new, 17th floor space atop the Auditorium Building, Wright soon earned a private office next to Sullivan's own. However, that office was actually shared with friend and draftsman George Elmslie, who was hired by Sullivan at Wright's request. Wright had risen to head draftsman and handled all residential design work in the office. As a general rule, Adler & Sullivan did not design or build houses, but they obliged when asked by the clients of their important commercial projects. Wright was occupied by the firm's major commissions during office hours, so house designs were relegated to evening and weekend overtime hours at his home studio. He would later claim total responsibility for the design of these houses, but careful inspection of their architectural style and accounts from historian Robert Twombly suggest that it was Sullivan who dictated the overall form and motifs of the residential works; Wright's design duties were often reduced to detailing the projects from Sullivan's sketches. During this time, Wright worked on Sullivan's bungalow (1890) and the James A. Charnley bungalow (1890) both in , Mississippi, the Berry-MacHarg House (1891) and Louis Sullivan's House (1892) both in Chicago, and the most noted 1891 James A. Charnley House also in Chicago. Of the five collaborations, only the two commissions for the Charnley family still stand