Silverton, Devon born centre forward Harold Blackmore played football for local junior clubs Silverton in 1922 and Bradninch in 1923 before he joined Exeter City in August 1924, making his Football League debut that October against Swindon Town and scoring 8 times in only 13 appearances during his debut season. He top scored for Exeter during 1926-27 with 25 goals by Easter which brought him to the attention of First Division Bolton Wanderers who signed him at the end of March 1927, Blackmore then scoring in his first two top flight games against Sheffield Wednesday and Leicester City.
After struggling for first team action in 1927-28 despite 4 goals in a match against Burnley in November 1927, he scored 30 goals in each of the next 3 seasons including 37 in 1928-29, top scoring each season albeit Bolton finished lower mid table every year. These feats included a further 4 goal haul against Everton in December 1929 and five other hat-tricks. He won the FA Cup with Bolton in 1929 as they beat Portsmouth 2-0 at Wembley with Blackmore sealing victory late on with the second goal. In June 1932, after 122 goals in 135 games, he joined Middlesbrough, where he had a single season scoring 12 goals in 23 games.
He moved to Bradford Park Avenue in May 1933, where he again topped the club goalscoring charts in 1933-34 with 27 strikes as Bradford finished 5th, and by the time he signed for Bury in January 1935 he’d scored 32 goals in 62 appearances. However his stay at Bury, after scoring in his first 3 games including a debut double against Brentford, lasted only 6 matches and he retired at the end of the season having scored well over 200 career goals.