List of Major League Baseball progressive single-season home run leaders
Single-season records

Batter
Team
Age
Year
HR
Reign
Record breaker
George Hall
Philadelphia Athletics
27
1876
5
3 years
—
Charley Jones
Boston Red Caps
29
1879
9
4 years
6th on July 31 off George Bradley
Harry Stovey
Philadelphia Athletics
27
1883
14
1 year
10th on August 1 off Jack Neagle
Ned Williamson
Chicago White Stockings
27
1884
27
35 years
15th on July 9 off Ed Bagley
Babe Ruth
Boston Red Sox
24
1919
29
1 year
28th on September 24 off Bob Shawkey
Babe Ruth
New York Yankees
25
1920
54
1 year
30th on July 19 off Dickie Kerr
Babe Ruth
New York Yankees
26
1921
59
6 years
55th on September 15 off Bill Bayne
Babe Ruth
New York Yankees
32
1927
60
34 years
60th on September 30 off Tom Zachary
Roger Maris
New York Yankees
27
1961
61
37 years
61st on October 1 off Tracy Stallard
Mark McGwire
St. Louis Cardinals
35
1998
70
3 years
62nd on September 8 off Steve Trachsel
Barry Bonds
San Francisco Giants
36
2001
73
17 years
71st on October 5 off Chan Ho Park

Question: What happened to the major league home run record after 1998?
Answer: In 1998, McGwire set the major league single-season home run record with 70, which was later broken by Bonds with 73.