The Grand Junction backed the Oxford & Rugby railway when its relations with the London & Birmingham were poor, so that it would have had a separate route to London via the GWR.
But of course it soon merged with the L&B and M&B to form the LNWR, and the Oxford & Rugby fell into GWR hands and headed to Birmingham instead.
Rugby was briefly a major node on the network, carrying all traffic from London to the north, but the Great Northern and then the Midland soon built their own routes direct to London.
Once the Wigston-Bedford-Hitchin line was opened by the Midland in 1857, the Rugby-Wigston line became a backwater after more than a decade of being a critical link in the rail network.
The GC, when it came in 1899, managed to route through Rugby without connecting to either the LNWR or the Midland on the way.
The 1850s marked merger negotiations between the LNWR and variously the Midland, GN, MS&L and L&Y, but were never concluded (though the L&Y was merged in 1921 just before grouping).
It was one of the strategic blunders of the Beeching era that we lost both Rugby-Leicester routes, when a connection between the WCML and MML would have been very valuable, particularly at times of disruption.
The retained connections at Bletchley, Nuneaton and Northampton (now also closed) were nothing like as effective as a Rugby-Leicester link would have been,