Lewis, a four-time U.S. Walker Cup team member and captain of the 2003 USA squad, played on victorious USA teams in 1981, 1983, 1985 and 1987 and compiled a 10-4 overall individual record. Only eight golfers have been named to more USA Walker Cup teams than Lewis. He also was the captain of the 2003 USA team that lost to its GB&I counterparts in September at Ganton Golf Club in England, 12 - 11.
A successful amateur golfer since his reinstatement in 1974, Lewis was the runner-up at three USGA championships and reached the semifinals twice more. In 1980, at age 35, he lost to Hal Sutton in the U.S. Amateur final. He was also the runner-up at the 1981 U.S. Mid-Amateur to Jim Holtgrieve, a former Walker Cup player and now a PGA Champions Tour player, and the 1984 Mid-Amateur to Mike Podolak. He was the co-medalist at the 1984 Mid-Amateur along with two-time Walker Cup captain Danny Yates.
In addition to his four international appearances as a Walker Cup team member, Lewis played on two U.S. World Amateur teams. The 1982 squad won the world title and the 1986 team finished second. As a foursomes partner with Holtgrieve, Lewis shares the record for largest margin of victory (7 and 6) in a Walker Cup match.