As US 51 crosses the state line, it enters the town of [[Osyka, MS|Osyka]], where it intersects [[Mississippi Highway 584|MS 584]]. The highway now travels several miles until having an intersection with [[Mississippi Highway 568|MS 568]]. The route soon after passes through [[Magnolia, Mississippi|Magnolia]] and has an intersection with [[Mississippi Highway 48|MS 48]]. Shortly after, US 51 passes through the community of [[Fernwood, Mississippi|Fernwood]] and continues north for a few miles. Eventually, the route enters [[McComb, Mississippi|McComb]] and intersects [[U.S. Route 98 in Mississippi|US 98]]. The highway now takes the name of S Broadway St. and passes through downtown McComb. Here it has an intersection with [[Mississippi Highway 570|MS 570]] and [[Mississippi Highway 44|MS 44]] (Pearl River Ave). Shortly after, US 51 takes a left turn onto W Georgia Ave and then hits a right curve and takes the name Jackson Ave. The route passes through residential area and hits a left curve to become Mississippi St and takes one last curve right to take the name Northwest Ave. US 51 soon intersects another segment of [[Mississippi Highway 570|MS 570]] (Veterans Blvd) before passing through [[Summit, Mississippi|Summit]]. The highway now travels north through thick forests to enter [[Lincoln County, Mississippi|Lincoln County]], where the route continues north through [[Norfield, Mississippi|Norfield]] and [[Bogue Chitto, Mississippi|Bogue Chitto]]. The highway travels north for several miles until reaching an intersection with [[U.S. Route 84 in Mississippi|US 84]]. US 51 now enters [[Brookhaven, Mississippi|Brookhaven]], passing through a major business area. The highway intersects [[Mississippi Highway 550|MS 550]] while crossing a railroad track. The route now continues north for a few miles before entering [[Copiah County, Mississippi|Copiah County]] and the town of [[Wesson, Mississippi|Wesson]]. US 51 travels through downtown and continues north for several miles. Eventually the highway enters [[Hazlehurst, Mississippi|Hazlehurst]] and passes through the downtown area. The route soon has an intersection with [[Mississippi Highway 28|MS 28]]. North of the city, US 51 traverses through more woods to pass through [[Gallman, Mississippi|Gallman]] and eventually crosses into [[Crystal Springs, Mississippi|Crystal Springs]], where the route mainly bypasses the town. US 51 now comes to an intersection with [[Mississippi Highway 27|MS 27]], where the routes takes a left turn onto MS 27 north. The two highway quickly has an interchange with [[Interstate 55 in Mississippi|I-55]] for US 51 to join I-55 in a concurrency towards [[Jackson, Mississippi|Jackson]]. The two routes soon enters [[Hinds County, Mississippi|Hinds County]] to pass through [[Terry, Mississippi|Terry]]. I-55 and US 51 shortly after passes through [[Byram, Mississippi|Byram]], where the two highways expand to a six-lane freeway to enter the city of [[Jackson, Mississippi|Jackson]].
As US 51 crosses the state line, it enters the town of [[Osyka, MS|Osyka]], where it intersects [[Mississippi Highway 584|MS 584]]. The highway now travels several miles until having an intersection with [[Mississippi Highway 568|MS 568]]. The route soon after passes through [[Magnolia, Mississippi|Magnolia]] and has an intersection with [[Mississippi Highway 48|MS 48]]. Shortly after, US 51 passes through the community of [[Fernwood, Mississippi|Fernwood]] and continues north for a few miles. Eventually, the route enters [[McComb, Mississippi|McComb]] and intersects [[U.S. Route 98 in Mississippi|US 98]]. The highway now takes the name of S Broadway St. and passes through downtown McComb. Here it has an intersection with [[Mississippi Highway 570|MS 570]] and [[Mississippi Highway 44|MS 44]] (Pearl River Ave). Shortly after, US 51 takes a left turn onto W Georgia Ave and then hits a right curve and takes the name Jackson Ave. The route passes through residential area and hits a left curve to become Mississippi St and takes one last curve right to take the name Northwest Ave. US 51 soon intersects another segment of [[Mississippi Highway 570|MS 570]] (Veterans Blvd) before passing through [[Summit, Mississippi|Summit]]. The highway now travels north through thick forests to enter [[Lincoln County, Mississippi|Lincoln County]], where the route continues north through [[Norfield, Mississippi|Norfield]] and [[Bogue Chitto, Mississippi|Bogue Chitto]]. The highway travels north for several miles until reaching an intersection with [[U.S. Route 84 in Mississippi|US 84]]. US 51 now enters [[Brookhaven, Mississippi|Brookhaven]], passing through a major business area. The highway intersects [[Mississippi Highway 550|MS 550]] while crossing a railroad track. The route now continues north for a few miles before entering [[Copiah County, Mississippi|Copiah County]] and the town of [[Wesson, Mississippi|Wesson]]. US 51 travels through downtown and continues north for several miles. Eventually the highway enters [[Hazlehurst, Mississippi|Hazlehurst]] and passes through the downtown area. The route soon has an intersection with [[Mississippi Highway 28|MS 28]]. North of the city, US 51 traverses through more woods to pass through [[Gallman, Mississippi|Gallman]] and eventually crosses into [[Crystal Springs, Mississippi|Crystal Springs]], where the route mainly bypasses the town. US 51 now comes to an intersection with [[Mississippi Highway 27|MS 27]], where the routes takes a left turn onto MS 27 north. The two highway quickly has an interchange with [[Interstate 55 in Mississippi|I-55]] for US 51 to join I-55 in a concurrency towards [[Jackson, Mississippi|Jackson]]. The two routes soon enters [[Hinds County, Mississippi|Hinds County]] to pass through [[Terry, Mississippi|Terry]]. I-55 and US 51 shortly after passes through [[Byram, Mississippi|Byram]], where the two highways expand to a six-lane freeway to enter the city of [[Jackson, Mississippi|Jackson]].
