She married her guardian, Gustav Modrzejewski, in 1861, and he helped her to get started in the theater when they together, joined a company of strolling players. Gustav Modrzejewski died in 1865 and shortly after, she married Count Karol Bozenta Chlapowski. She decided however, to retain the normal, grammatically-feminine form of her first husband's surname, Modrzejewska. She later, when acting outside Poland, used an "anglicized" version of her name – Modjeska, which was easier for English-speaking audiences to pronounce.

She died on April 8, 1909, aged 68, in California.

In 1910 a theatre was built on Mitchell Street, Milwaukee to honor Helena Modjeska. This Modjeska Theatre was a brick building with 840 seats. Little is recorded about the theatre and its design at this time besides the fact that it had an ornate wooden facade.

In 1924, the Saxe theatre chain bought and demolished the building, erecting, on the site, a new Modjeska Theatre – the building which remains with us today. It was the first of four theatres in Milwaukee that architechs Rapp & Rapp  of Chicago, would design (the others being Wisconsin in 1924, Uptown in 1926 and Warner, 1931).

The new Modjeska was fully equipped for vaudeville, as well as movies, with twenty trap doors on the stage, and a large orchestra pit. A Barton pipe organ was added to accompany movies, shown at that time. Due to budget restraints however, the theatre was one of Rapp & Rapp's least decorative. A large dome with cove lighting, instead of their usual elegant chandeliers, served as the primary illumination. 

In 1927, it became part of the Fox Theatre chain, but by the 1940s was a United Artists house. During this time, the Modjeska and the Granada (directly across the street) would show daily matinees of Polish films, to accommodate the ethnic makeup of the neighborhood.

In the 1950s the organ and pipes were removed to accomodate the installation of air-conditioning in the theatre. 

The theatre closed on December 31, 1989, but in 1991 was purchased by local businessman Stewart Johnson. The theatre has been sympathetically remodeled, with the removal of two dozen front rows to provide a dance/events floor. A unique doorway now joins the balcony foyer to a new screening room on the building's second floor. The box office and facade of the theatre have been largely restored.

The theatre is unusual in that there are overview portals in the balcony foyer walls which look down upon the orchestra seats below. This feature was only in one other Milwaukee theatre, the Wisconsin, which was demolished in 1986. The portals allowed patrons, who needed to be out in the foyer promenade, to continue enjoying a performance. It did, however, allow noise to penetrate into the auditorium and it became necessary that they be boarded up.

In 2005, the Modjeska Youth Theatre Company purchased the venue and now continue to show many live productions with local talent.

The new owners continue to restore this historic building.