Sam Grant is a sequel/companion game to Bobby Lee, Columbia Games' strategic-level block wargame about the Eastern Theater in the American Civil War, which moves the action out west where Union general Ulysses S. Grant made his reputation. The major difference between the two games is the hex scale, although this ends up having no real effect on play.
Initially there were some minor differences between the two games, but the latest rules from Columbia Games are a consolidated set covering both games.
In both games, units are depicted with wooden blocks with stickers on one side showing the unit type and strength. For those unfamiliar with the block games, the blocks are usually on end, Stratego-style. This provides fog of war while also providing a simple method of showing losses by rotating the block as it takes losses.
Columbia evidently went through a graphics upgrade between the 1993 Bobby Lee and the 1997 Sam Grant because the newer game's stickers are considerably better looking. The older game has very stark NATO-style unit symbols in colored lines (blue = inf, red = arty, yellow = cav) with varying numbers of "pips" on each edge for strength. This is little different from Quebec 1759 back in 1972! In Sam Grant we see the first inklings of a Columbia's more attractive later graphics, although they're still on the plain side. They are much more legible, however, with the pips replaced with numbers and the lines replaced with colored unit symbol squares (same blue/red/yellow).
The most important units in the game are headquarters. Similar to the system used in the Front series of games, there are army-level field headquarters that control regular movement and combat and a supreme headquarters that can move units via strategic means such as railroads and rivers or be used to move individual units outside command range of a field army HQ. Unlike the Front games, HQs in Sam Grant always have the same command range -- 1 hex for US, 2 for CS.
Battles are resolved in-hex in multiple rounds on a separate battle board divided into left, center, right and reserve sections. It's basically the standard Columbia battleboard system with some minor changes to account for Civil War era tactics such as no infantry squares and the presence of heavy artillery.
Every turn is a month, and as in usual Columbia practice there are seasonal scenarios, in this case one per year. Unlike the war in the East, where players will march back and forth over the same ground for four years, the Union has the potential to make steady progress. There are just three start points (1862, 1863 and 1864) and the game won't go on into 1865 as the historical action after that moved off map.
The common opinion is that 1862 scenario is somewhat of a problem because it's harder for the Union to break the river line under game conditions than history, which tends to throw the pace of the campaign off. Players therefore may want to start with the 1863 campaign which starts with that river line already breached.
Sam Grant can be combined with Bobby Lee for a grand campaign game suitable for four players. Units can be transferred between theaters, which opens up some interesting strategic possibilities. Historically both sides transferred significant forces between the theaters, especially in 1863.
Sam Grant is a little more involved than typical Columbia fare such as Hammer of the Scots or Crusader Rex and playing a multi-year campaign game will take more than an evening. On the other hand, it's not as big a project as a Front series game like EastFront.
It's a good choice for fans of block games, although the pacing might be a little slow for current tastes.