It took General Motors and the UAW a summer of negotiations and a national strike lasting almost six weeks to reach a new contract on wages, benefits and job security. The agreement includes a commitment by GM to invest $1.5 billion to modernize and expand its 36-year-old Wentzville Assembly plant, just west of St. Louis. But the October agreement was merely the latest hurdle cleared for the Wentzville plant’s rejuvenation. In May, Missouri Gov. Mike Parson united city, county and state leaders to assemble an incentives package to provide GM with $50 million spread out over 10 years for the project, if it were to go forward. That plan had been temporarily held up by a group of Missouri state senators who decried accompanying legislation that gave Missouri’s economic development arm the ability to grant “upfront incentives” to attract additional industry.