The broad gauge line from Crediton to Barnstaple was opened in 1854. The original Fremington Docks line was also converted to broad gauge but still remained goods only. Passenger trains from Barnstaple to Crediton continued over the Exeter & Crediton Railway to Exeter St Davids. The North Devon Railway was amalgamated with the LSWR in 1865

When the North Devon Railway was opened to Barnstaple the extension to Bideford was already under construction and completed the next year. The railway was extended from Fremington through Instow to the original station at Cross Parks at East the Water in Bideford.

The Exeter trains to Barnstaple continued to Bideford. The Extension Railway was financially stronger than the North Devon Railway, although in 1862 it was leased by the LSWR and amalgamated along with the North Devon Railway in 1865.

The LSWR reached Exeter Queen Street in 1860. This heralded the beginning of the end of broad gauge in north Devon. Mixed gauge was laid to Bideford in 1863, and the final broad gauge local trains ran in 1877 after which the whole route was changed to standard gauge only. In 1872 the line had been extended as standard gauge only to Torrington and the current station had been built in Bideford. The old station at Cross Parks became the goods yard.

Bideford Goods Junction signalbox, which controlled the entrance to the goods yard once the line had been extended to Torrington. This was later replaced by a ground frame.

The viaduct over Fremington Pill was wooden with a lifting span to allow vessels to pass up the Pill. This unsatisfactory arrangement was solved by 1880 when the current iron bridge could be built because the LSWR had purchased the right of way to navigate Fremington Pill.

Two other major routes were opened in north Devon: the GWR from Taunton to Barnstaple via South Molton and the LSWR route to Ilfracombe. The Torrington line was always regarded by the LSWR as the main line for trains from Exeter.

The main LSWR locomotive shed was at Barnstaple Junction with some locomotives based at the Torrington sub-shed. Visiting locomotives to north Devon were based at Exmouth Junction shed, east of Exeter.

The LSWR became a constituent of the new Southern Railway when the Big Four were formed at the 1923 grouping of the country’s railways. The first effects in North Devon was the increasing of capacity at Barnstaple Junction station, coupled with through trains from Exeter being routed to Ilfracombe rather than Torrington. New N Class locomotives appeared on these Ilfracombe trains and the Torrington line was relegated to a branch line, with M7 and E1r tanks working the traffic. However, through coaches to Torrington from London were continued on principal trains. The famous Atlantic Coast Express was established in 1926.

In 1925 the light railway extension from Torrington to Halwill Junction opened, largely to serve the china clay works at Meeth.

By 1935 bus competition was becoming stronger and private cars were becoming more commonplace. This led to the first railway closure in North Devon: the Lynton & Barnstaple Railway in the September of that year.

For a few years after the war North Devon was graced with the short-lived Devon Belle Pullman which ran through from London to Ilfracombe.