"Steroids were part of the game, and I don't think anybody really wanted to take a stance on it," Canseco said. "If Congress does nothing about this issue, it will go on forever."

Several congressmen gushed about the sport, recalling how as children they collected baseball cards and autographs and looked up to players. With rare exceptions, members of the committee appeared deferential and unwilling to press the players, saving their harshest criticism for baseball officials.

"Why should we believe that the baseball commissioner and the baseball union will want to do something when we have a 30-year record of them not responding to this problem?" asked Rep. Henry Waxman of California, the committee's ranking Democrat.

The wood-paneled hearing room was full when the players appeared, with camera crews lining the walls and clogging the aisles. Much of the crowd cleared out when the players left, leaving empty seats for Major League Baseball Commissioner Bud Selig's testimony.

Lawmakers questioned baseball's new drug-testing plan, including a provision allowing for fines instead of suspensions. A first offense could cost 10 days out of a six-month season, or perhaps a $10,000 fine.

But Selig said he would suspend anyone who fails a test, adding: "There will be no exceptions."

While boosting strength, steroids also can lead to dramatic mood swings, heart disease, cancer, sterility and depression; using most steroids without a doctor's prescription for medical purposes has been illegal since 1991.

Baseball banned steroids in September 2002 and began testing for them with penalties in 2004.

Questions about steroids in baseball have intensified as home runs have increased. McGwire and Sosa were widely credited with helping restore baseball's popularity in 1998 when they chased Roger Maris' season record of 61 homers. McGwire ended up with 70, a mark that lasted only three seasons before Barry Bonds of the San Francisco Giants hit 73.

Bonds and Jason Giambi of the New York Yankees were not called to the hearing. They testified in 2003 to a San Francisco grand jury investigating a steroid-distribution ring, and there were concerns if they spoke to Congress it could hinder the probe.

Baseball fought attempts to compel players to testify, but Waxman and committee chairman Tom Davis, R-Va., threatened to pursue contempt charges.

More than four hours after the hearing began, the players walked in one by one. Boston Red Sox pitcher Curt Schilling, a vocal critic of steroid use, was the first to enter. He sat at one end of the witness table, with Canseco at the other. Palmeiro, Sosa and McGwire were in between.

Schilling took a shot at Canseco, saying claims in the former slugger's book "should be seen for what they are: an attempt to make money at the expense of others."

But Schilling also backtracked from his earlier claims of rampant steroid use, saying, "The issue was grossly overstated by people, including myself." He estimated that only five to 10 of his teammates in the past 15 years used steroids but said he had never actually seen anyone take the drugs.