He was the son of John Logan of Newport, Monmouthshire and educated at King's School, Gloucester. J. W. Logan was a successful railway contractor with the civil engineering firm of Logan and Hemingway. He moved to Leicestershire in 1876 to supervise a railway contract and lived near Market Harborough at East Langton Grange, where he gave the village a cricket ground and a hall. He also maintained a cottage home for the children of men killed on his works.[2]
His health was poor following a hunting accident and he resigned as MP on two occasions. Logan had won Harborough from the Tories at a by-election on 8 May 1891 and held it until his resignation on 1 June 1904.[3] He returned at the second general election of 1910, only to resign again six years later.[3] His political career was devoted to improving the lot of agricultural labourers, and it was in their interests that he had agreed to stand for parliament on the second occasion, but the strain proved too great, forcing him to retire permanently from public life.[4]
During his election campaigns, he was often denied the use of public halls and held his meetings under canvas in what he called the "free speech tent".[4]
On his death at the age of 80 in 1925, he was buried at East Langton, where he had lived for 50 years.[4] During his life he also visited Australia and New Zealand.