1920s had seen the stags take a giant leap forward, with the 1928/9
season being exceptionally successful. As the 1929/30 season dawned it
looked as though the glory days were to continue particularly as Town
started the league programme with seven straight wins. This success
could not be maintained, however, and of the next seven only one was won
as the Stags had an up and down season eventually finishing in a
disappointing 10th position. There was no success in the FA Cup either
as, exempt until Round 1, they were dumped out by now defunct Manchester
Central. The usual application for Football League status was again
forthcoming and once again the Town officials left the meeting
disappointed as Halifax and Barrow were re-elected, the latter
collecting just 7 more votes than the Stags.
1930/1 was another topsy-turvy affair for the Stags, 12 of the last 18
matches were lost and once again only a mid-table 10th position was
achieved. There was a little more success in the cup competitions where
the Stags reached the First Round of the FA Cup and won the Notts Senior
Cup. In the FAC Cup Town were exempt until the 4th Qualifying Round
where a team from Rotherham call Highgate were stuffed by the amazing
score of 10-1 (still the Club's record FA up win). In Round 1, Town
visited Halifax and came away with a creditable draw, but succumbed 1-2
in the replay at Field Mill. In the Senior Cup Notts County's reserve
side were beaten 7-0 in the final on the ground of Newark Town.
the summer Town renewed their campaign for Football League status. For
months before the League's AGM, Town's officials had been canvassing for
support. They also decided to change tack and apply for membership of
the Southern Section of Division 3 in an attempt to win the support of
the northern clubs. The tremendous amount of work put in by all
concerned paid off as when the votes were counted the Stags (25 votes)
finished second to Norwich City (38 votes) and replaced Newport County
(19 votes) in the Southern section for the 1931/2 season. At last
Mansfield Town were in with the 'big boys'!
amazing 23 players were signed for the new season, including 32 year old
Harry Johnson Sheffield United's record scorer. On the League's opening
day over 12,000 spectators entered Field Mill for the historic match
with Swindon Town. The Stags ran out 3-2 winners, Joe Readman having the
honour of scoring the Stags first League goal. On the whole it was a
difficult season with Town finishing one place (4 points) away from
applying for re-election. Although Johnson scored 32 goals, the defence
conceded over 100 and with only 5 points won (no victories) away from
home it was not the start hoped for. There was no success in the FA Cup
as the Stags bowed out at the first attempt away at Hull City.
At the League's AGM Town were transferred to the Northern section to replace Wigan Borough who had folded during the previous season. The Northern section was considered to be of a lower standard than the Southern, but Town did not improve much only to 16th place. Two records were set which still stand today, Rotherham United were beaten 9-2 for the record League victory and only 23 days later the team were beaten 1-8 at Walsall for the record defeat. The first away victory came in March, the 38th match on their travels since joining the League. Walsall also ended the Stags FA Cup dreams in the first round, winning by 4 goals to 1.
In the summer of 1933 the Stags became the first club to introduce installment payments for season tickets. Another mediocre season in the League left the Stags in 17th place. In the FA Cup Town at least this season managed a replay in the first round before losing to New Brighton in that replay at Field Mill. The directors made a change in manager in December 1933 when they sacked Jack Hickling and installed Harry Martin in the hot seat. Harry Johnson's goal scoring prowess dimmed this season, having scored 32 in the first season and 30 the next year this time he could only manage 18!
1934/5 saw some improvement in the league position when for the first time Town finished in the top half of the table, a creditable 8th place overall. There was also some improvement in the FA Cup where the Third Round was reached. After defeating Accrington Stanley and Tranmere Rovers at Field Mill, First Division Burnley defeated the Stags 4-2 at Turf Moor. Off field Harry Martin's tenure as manager ended in March when he was surprisingly sacked and replaced by Charlie Bell. Harry Johnson scored another 17 goals to take his impressive tally to 97 in League matches.
By the end of September 1935 Harry Johnson had scored his 100th league goal for the club, but it was obvious that he was near the end of his career. Manager, Charlie Bell, reacted by obtaining the services of Teddy Harston from Bristol City. He made an immediate impact by scoring a hat trick on his debut at Southport in October. In spite of Harston's contribution of 26 goals, Town had another 'in and out' finished in only 19th position. Johnson retired at season's end with a club record 104 league goals. There was another change in managership this season when Charlie Bell resigned in December. Harry Wightman was selected by the directors as Bell's replacement, however, he took the job only until the end of the season. Another first round FA Cup defeat (2-3 at home to Hartlepool) underlined the Stags disappointing season on the pitch.
With Harry Parkes in place as the new manager there was plenty of excitement on the pitch as the Stags climbed into 9th position. This would, no doubt, have been much better had there been more support for Teddy Harston who excelled himself by scoring an amazing 55 goals in 41 league games. His incredible haul included one 7, two 5s a four and three hat tricks. For good measure he notched another treble in the FA Cup as the Stags reached the second round. The Notts FA also introduced the County Cup for the first time this season. Unlike today the major non-league side were invited to participate to make up the four for the semi finals. The Stags made an inauspicious start in the competition losing 1-5 to Notts County. Not surprisingly Town accepted Liverpool's offer for the hit man and he joined the Reds for the start of the new season. Harry Crawshaw came to Field Mill as a replacement. Town were also transferred into the Southern Section for the 1937/8 season
Although the new striker emulated Harston by scoring a hat trick on his debut, and his 25 goals in the 1937/8 season made him the Southern Section's leading marksman, Town could only manage a below par 14th place. In the FA Cup the Stags were quite successful in reaching Round 3 where after disposing of Wellington Town and Lincoln City, First Division Leicester City proved too strong and won 2-1 in front of a new record crowd (15,890) at Field Mill. Town did capture some silverware though when, after defeating Newark Town in the semi final, Nottingham Forest were beaten 2-1 in the final of the County Cup. In January 1938 the merry go round in the managers office continued as Harry Parkes left the club to be replaced by Jack Poole.
In the summer of 1938, Harry Crawshaw left Field Mill for Nottingham Forest a move which left the Stags short up front the following season. The Stags finished in 16th place in 1938/9 the goals for tally of 44 showed exactly what the problem was, the leading scorer this time was Dutton with a paltry 12. In the FA Cup Town reached Round 2, defeating Workington in the first round before losing to Halifax Town at Old Trafford in a second replay in that second round. In the County Cup Town again reached the final where they drew 2-2 with Nottingham Forest. Due to the actions of a certain Mr Hitler the match was never replayed and the competition remained in abeyance until the 1960s.