Complex sentence: In 1953, his 50 year association with Thayer Coggin Inc. began and by the 1960s and 1970s, his new collection was eagerly awaited at the High Point Market every year.
Split into simpler sentences: In 1953, his 50 year association with Thayer Coggin Inc. began. By the 1960s and 1970s, his new collection was eagerly awaited at the High Point Market every year.