Raff's music was very popular in the United States and his rise to fame there came very soon after he burst upon the European scene. Barely a year after the publication of his Symphony No.1 An das Vaterland, which had catapulted him to fame by winning a prestigious prize in Vienna, it was played in New York. Over the next forty years his orchestral music was a staple of the US repertoire and works such as the Lenore Symphony were very popular. Much of Raff's success across the Atlantic can be attributed to the tireless championing of it by a German immigrant who founded the Chicago Symphony Orchestra and is today regarded as his adopted country's first great conductor.

Theodore Thomas (1835-1905) was born and spent the first ten years of his life in Germany. By the time he arrived with his family in New York he was already an accomplished musician and he was soon playing in the city's theatre orchestras. As a youth he toured the country giving violin recitals, but he returned to New York when he was fifteen to study conducting and become a violinist in the Philharmonic Society's orchestra. He also joined forces with the pianist and composer William Mason (a friend of Raff's from their Weimar days) to form the Mason-Thomas quartet. In 1862 he founded the Theodore Thomas Orchestra with which he toured the eastern US for 16 years until it was disbanded after suffering financial problems.

From 1877 he frequently conducted the New York Philharmonic Orchestra until in 1891 he became the Chicago Symphony Orchestra's founding conductor. When he had been asked, a couple of years earlier if he would go to Chicago if he was given a full-time, professional orchestra, he famously replied "I would go to hell if they gave me a permanent orchestra". His early espousal of Raff was typical of his forward looking approach to concert programming; in Chicago he gave the US premier of works by Bruckner, Elgar, Tchaikovsky and Richard Strauss amongst many others. His wife wrote of him: "He not only disciplined his musicians, but he disciplined the public, educating it sometimes perhaps against its will."

Thomas' dedication to Raff is evident from the large number of Raff scores in his collection (available for viewing at the Chicago Symphony Orchestra archive). In all he gave the US premieres of a dozen of Raff's works, starting with the Symphony No.1 in New York on 18 February 1865, almost two years to the day after it was first heard in Vienna. Thomas was even quicker off the mark with his performance of the Symphony No.5 Lenore in Boston on 5 December 1873; the work's first public performance had been in Berlin only only a month earlier on 29 October. The Sixth Symphony was also debuted in the US by Thomas. It was first heard in a New York concert on 8 January 1875, less than three months after its Berlin premiere.

The reputations of both Raff and Thomas at this time can be judged by this extract from the journal Brainard's Musical World, of February, 1874: "Thomas's orchestra is gaining fame abroad. Liszt, Raff, and Wagner express a desire to have their works performed by this society, and Raff has recently composed for Thomas a suite in five numbers for solo violin and grand orchestra". Although the Suite for Violin & Orchestra op.180 was indeed composed in autumn 1873, there is no other evidence that it was written for Thomas. It was dedicated to the violinist Hugo Heermann and had already been premiered in Germany when Brainard's article was written.

Thomas eventually gave eleven Raff US premieres over 23 years. In addition to the three symphonies, these were:

The performance in 1875 of the Sinfonietta appears to be only its second airing and Thomas' Hungarian Suite in the following year was the work's third performance. He conducted many other Raff works, including the Second Symphony, the Fourth Symphony and the Piano Concerto, and he continued to programme the composer's orchestral works once he became the permanent conductor of the Chicago Symphony Orchestra. Raff's high reputation in the United States as a result of Thomas' fine performances is amply demonstrated by his friend George Upton's view of the symphonies in his book The Standard Symphonies.

Thomas died at the height of his powers not long after inauguarating the Chicago Symphony orchestra's permanent home. In flowery 1920s prose, his biographer Charles Edward Russell wrote: "He had great and unaccountable gifts in his art, native gifts largely untrained, but indomitably efficient for the work he was to do... In forty-three years he led more than ten thousand concerts for which he made all the selections. Among all these is virtually none that was not fitted thoughtfully into his great design. Other conductors played for today and often played magnificently; he alone played for tomorrow and all the tomorrows that are to be... The lives of millions of people are the brighter or the more endurable because of the work to which Theodore Thomas gave himself with all his heart and with all his soul and all his mind and all his strength". Raff could not have hoped for a finer advocate in the New World.