Complex sentence: In 1947 he was invited to the Unites States by the New York gallery Portraits, Inc. Conde Nast Publications commissioned him to paint a number of important American houses and the publication of these works led to more commissions in the United States.
Split into simpler sentences: In 1947 he was invited to the Unites States by the New York gallery Portraits, Inc. and Conde nast Publications commissioned him to paint important American houses. The publication of these works led to more commissions in the United States.